A- (3) prefix meaning "not," from Gk a-, an- "not," from pie base *ne "not" (see un-)

ultralight (adj.) --- 1974, from ultra- + light (adj.). As a noun meaning "ultralight aircraft" it is recorded from 1982.

ultramarine --- 1598, "blue pigment made from lapis lazuli," from M.L. ultramarinus, lit. "beyond the sea," from ultra- "beyond" + marinus "of the sea." So called because the mineral was imported from Asia by sea.

ultramontane --- 1592, from M.Fr. ultramontain "beyond the mountains" (especially the Alps), from O.Fr. (1323), from L. ultra "beyond" + stem of mons (see mountain). Used especially of papal authority, though "connotation varies according to the position of the speaker or writer." [Weekley]

ultrasonic --- 1923, "having frequency beyond the audible range," from ultra- + sonic. For sense, see supersonic. First record of ultrasound is from 1923; in ref. to ultrasonic techniques of detection or diagnosis it is recorded from 1958.

ultraviolet --- beyond the violet end of the visible spectrum, 1840, from ultra- + violet. Ultra-red (1870) was a former name for what now is called infra-red.

ululation --- 1599, from L. ululationem (nom. ululatio) "a howling or wailing," from pp. stem of ululare "ululate," a reduplicated imitative base (cf. Gk. ololyzein "to cry aloud," Skt. ululih "a howling," Lith. uluti "howl," Gael. uileliugh "wail of lamentation," O.E. ule "owl").

Ulysses --- L. name for Odysseus, from L. Ulysses, Ulixes. Famous for wandering as well as craftiness and ability at deceit. For -d- to -l- alteration, see lachrymose.

um --- a sound denoting hesitation, 1672.

Umayyad --- member of a Muslim dynasty which ruled the Caliphate 661-750 C.E. and in 756 C.E. founded an emirate in Spain, 1758, from Arabic, from Umayya, proper name of an ancestor of Muhammad from whom the dynasty claimed descent.

umber --- brown earthy pigment, 1568, from M.Fr. ombre (in terre d'ombre), or It. ombra (in terra di ombra), both from either L. umbra "shade, shadow" (see umbrage) or from Umbra, fem. of Umber "belonging to Umbria," region in central Italy from which the coloring matter first came. Burnt umber, specially prepared and redder in color, is attested from c.1650.

umbilical --- pertaining to the navel, 1541, from M.L. umbilicalis "of the navel," from L. umbilicus "navel," from PIE *onobh- (source of Gk. omphalos and related to *nobh, source of navel). First record of umbilical cord is from 1753. Umbilicus for "navel" is attested from 1693 but mostly is confined to medical writing.

umbles --- edible inner parts of a deer or other animal, c.1400, see humble.

umbra --- 1599, "phantom, ghost," a fig. use from L. umbra "shade, shadow" (see umbrage). Astronomical sense of "shadow cast by the earth or moon during an eclipse" is first recorded 1679. Meaning "an uninvited guest accompanying an invited one" is from 1696.

umbrage --- 1426, "shadow, shade," from M.Fr. ombrage "shade, shadow," from L. umbraticum, neut. of umbraticus "of or pertaining to shade," from umbra "shade, shadow," from PIE base *andho- "blind, dark" (cf. Skt. andha-, Avestan anda- "blind, dark"). Many fig. uses 17c.; main remaining one is the meaning "suspicion that one has been slighted," first recorded 1620; hence phrase to take umbrage at, attested from 1680.

umbrageous --- shady, 1587, from Fr. ombrageux, from O.Fr. umbrageus, from umbre "shade," from L. umbra (see umbrage).

umbrella --- 1609, first attested in Donne's letters, from It. ombrello, from L.L. umbrella, altered (by influence of umbra) from L. umbella "sunshade, parasol," dim. of umbra "shade, shadow" (see umbrage). A sunshade in the Mediterranean, a shelter from the rain in England; in late 17c. usage, usually as an Oriental or African symbol of dignity. Said to have been used by women in England from c.1700; the first rain-umbrella carried by a man there was traditionally c.1760, by Jonas Hathaway, noted traveler and philanthropist. Fig. sense of "authority, unifying quality" (usually in a phrase such as under the umbrella of) is recorded from 1948.

umiak --- large Eskimo boat, c.1743, from Eskimo umiaq "an open skin boat." Said by 18c.-19c. sources to be a "woman's boat," as opposed to the kayak, which was worked exclusively by men.

umlaut --- 1852, from Ger., "change of sound," from um "about" (see ambi-) + laut "sound," from O.H.G. hlut (see listen). Coined 1774 by poet Friedrich Gottlieb Klopstock (1724-1803) but first used in its current sense 1819 by linguist Jakob Grimm (1785-1863).

umma --- the Islamic community, founded by Muhammad and bound to one another by religious ties and obligations, 1855, from Arabic 'umma "people, community, nation."

umpire --- c.1400, noumper, from O.Fr. nonper "odd number, not even," in reference to a third person to arbitrate between two, from non "not" + per "equal," from L. par. Initial -n- lost by c.1440 due to faulty separation of a noumpere, heard as an oumpere. Originally legal, the gaming sense first recorded 1714 (in wrestling). Short form ump is attested from 1915. The verb is first recorded 1609, from the noun.

umpty --- 1905, "of an indefinite number," originally Morse code slang for "dash," influenced by association with numerals such as twenty, thirty, etc.; umpteen (1917) is World War I army slang, from umpty + teen.

un- (1) --- prefix of negation, O.E. un-, from P.Gmc. *un- (cf. O.Fris., O.H.G., Ger. un-, Goth. un-, Du. on-), from PIE *n- (cf. Skt. a-, an- "not," Gk. a-, an-, O.Ir. an-, L. in-), a variant of PIE base *ne- "not" (cf. Avestan na, O.C.S., Lith. ne "not," L. ne "that not," Gk. ne- "not," O.Ir. ni, Corn. ny "not"). Freely and widely used since O.E. times in compounds with native and imported words, it disputes with Latin-derived cognate in- the right to form the negation of certain words (indigestable/undigestable, etc.). Often euphemistic (e.g. untruth for "lie"). The most prolific of Eng. prefixes, it even is used to make words from phrases (e.g. uncalled-for, 1610; undreamed-of, 1636; uncome-at-able, 1694; unputdownable, 1947, of a book). As a prefix in telegram-ese to replace not and save the cost of a word, it is first attested 1936.

un- (2) --- prefix of reversal (e.g. unhand, undo, unbutton), O.E. on-, un-, from P.Gmc. *andi- (cf. O.S. ant-, O.N. and-, Du. ont-, O.H.G. ant-, Ger. ant-, Goth. and- "against"), from PIE *anti "facing opposite, near, in front of, before" (see ante).

unabated --- 1611, from un- (1) "not" + pp. of abate.

unable (adj.) --- c.1380, from un- (1) "not" + able. Modeled on O.Fr. inhabile or L. inhabilis.

unabridged --- 1599, from un- (1) "not" + pp. of abridge. Since 19c. chiefly in ref. to literary works.

unacceptable --- 1483, from un- (1) "not" + accept + -able.

unaccompanied --- 1545, "not in the company of others," from un- (1) "not" + pp. of accompany. Musical sense is first recorded 1818.

unaccountable --- 1643, "inexplicable," from un- (1) "not" + account + -able. Meaning "not liable to be called to account" is recorded from 1649.

unaccustomed --- 1526, "not customary, unfamiliar," from un- (1) "not" + pp. of accustom. Meaning "not accustomed or habituated" (to) is first attested 1611.

unacquainted --- 1529, from un- (1) "not" + pp. of acquaint.

unadorned --- 1634, from un- (1) "not" + pp. of adorn.

unaffected --- c.1586, "not influenced, untouched in mind or feeling," from un- (1) "not" + pp. of affect. Meaning "not adopted or assumed, genuine" is recorded from 1592; that of "not acted upon or altered (by something)" is first attested 1830.

unafraid --- 1423, from un- (1) "not" + afraid.

unaided --- 1667, from un- (1) "not" + pp. of aid.

unaltered --- 1551, from un- (1) "not" + pp. of alter. Unalterable is attested from 1611.

unambiguous --- 1751, from un- (1) "not" + ambiguous.

un-American --- 1818, from un- (1) "not" + American (see America).

unanimous --- 1611 (implied in unanimously), from L. unanimus "of one mind," from unus "one" (see one) + animus "mind" (see animus). Unanimity is recorded from 1436, from O.Fr. unanimite (14c.), from L. unanimitas, from unanimus.

unanswered --- 1390, from un- (1) "not" + pp. of answer.

unapproachable --- 1581, of places, from un- (1) "not" + approach + -able. Of persons, "distant, aloof," attested from 1848.

unarmed --- 1297, from un- (1) "not" + pp. of arm (v.).

unasked --- c.1255, "uninvited," from un- (1) "not" + pp. of ask.

unassisted --- 1614, from un- (1) "not" + pp. of assist.

unassuming --- unpretentious, 1726, from un- (1) "not" + inf. of assume.

unattached --- 1498, "not arrested or seized," from un- (1) "not" + pp. of attach. Meaning "not associated with any body or institution" is recorded from 1796; sense of "single, not engaged or married" is first attested 1874.

unattainable --- 1662, from un- (1) "not" + attain + -able.

unattractive --- 1775, from un- (1) "not" + attractive (see attract).

unauthorized --- 1596, from un- (1) "not" + pp. of authorize.

unavailable --- 1549, "ineffectual," from un- (1) "not" + avail + -able. Meaning "incapable of being used" is recorded from 1855. Unavailing (1670) has taken up the older sense of the word.

unavoidable --- 1577, from un- (1) "not" + avoid + -able.

unawares --- 1535, "without being aware," from un- (1) "not" + aware + adverbial genitive -s. Meaning "without being noticed" is recorded from 1667. Form unaware is recorded from 1592.

unbalanced --- 1650, from un- (1) "not" + pp. of balance. Earliest use is in ref. to the mind, judgment, etc. Of material things, it is recorded from 1732.

unbearable --- c.1449, from un- (1) "not" + bear (v.) + -able.

unbeaten --- c.1275, "not beaten or struck," from un- (1) + pp. of beat. In the sense of "undefeated" it is first recorded 1757.

unbecoming --- 1598, from un- (1) "not" + becoming "fitting" (see become).

unbeknownst --- 1848, vulgar formation from unbeknown (1636). No clear reason for the -st, but since 19c. this has become the dominant form.

unbelief --- c.1160, "absence or lack of religious belief," from un- (1) "not" + belief. Unbelievable is first attested 1548; unbeliever "infidel" is recorded from 1526.

unbend --- to relax a bow by unstringing it, c.1250, from un- (2) + bend. Fig. meaning "to become genial, relax" (1748) has a sense opposite to that of unbending "inflexible, obstinate" (1688), which does not derive from the bowstringing image.

unbeseeming --- 1583, "not befitting, inappropriate," from un- (1) "not" + beseeming. A common 17c. word.

unbiased --- 1607, lit., in ref to throws at bowls, from un- (1) "not" + pp. of bias. Fig. sense of "impartial, unprejudiced" is recorded from 1647.

unbidden --- O.E. unbedene, "not asked or invited," from un- (1) "not" + pp. of bid. Cf. M.Du. ongebeden, Ger. ungebeten, O.N. ubeðinn.

unbind --- O.E. unbindan, "to free from binding," from un- (2) + bind. Cf. Ger. entbinden, Du. ontbinden. Lit. and fig. senses both present in O.E.

unblemished --- c.1300, from un- (1) "not" + pp. of blemish. Originally in moral sense; material sense is attested from c.1450.

unborn (adj.) --- O.E. unboren "not yet born, stillborn," from un- (1) "not" + born. Cf. O.Fris. unbern, Du. ongeboren, O.H.G. ungiporan, Ger. ungeboren.

unbounded --- 1598, "not limited in extent," from un- (1) "not" + pp. of verb form of bound (n.). Sense of "generous, profuse, liberal" is recorded from 1704.

unbreakable --- c.1480, from un- (1) "not" + break + -able.

unbridled --- c.1374, originally in fig. sense of "unrestrained, ungoverned," from un- (1) "not" + bridled (see bridle). Cf. M.Du. ongebreidelt. Lit. sense of "not fitted with a bridle" (of horses) is not recorded before 1553. The verb unbridle is attested from c.1400 in the lit. sense; c.1440 in the fig. sense.

un-British --- 1746, from un- (1) "not" + British.

unbroken --- c.1300, in ref. to vows or compacts, from un- (1) "not" + pp. of break. Attested from 1495 in ref. to material things; 1513 in ref. to courage, spirit, etc.; 1538 in ref. to horses; 1561 in ref. to the flow of time.

unbuckle --- c.1386, from un- (2) + buckle (v.).

unburden --- 1538, "to unload" (trans.), from un- (2) + burden (v.). Cf. Ger. entbürden. Refl. sense is recorded from 1589.

unburied --- O.E. unbyrged, from un- (1) "not" + pp. of bury (v.).

unbutton --- c.1325, from un- (2) + button (v.).

uncalled --- c.1400, "not summoned," from un- (1) "not" + pp. of call (v.). Cf. Swed. okallad, Dan. ukaldet. With for and sense of "unnecessary, intrusive" it is first attested 1610.

uncanny --- 1596, "mischievous;" 1773 in the sense of "associated with the supernatural," originally Scottish and northern English, from un- (1) "not" + canny.

uncertain --- c.1300, "of indeterminate time or occurrence," from un- (1) "not" + certain (adj.). Meaning "not fully confident" is recorded from c.1380 (implied in uncertainty).

unchain --- 1582, from un- (2) + chain (v.). Fig. sense of "to liberate" is recorded from 1793.

unchanged --- 1387, from un- (1) "not" + pp. of change (v.). Unchangeable is attested from 1340.

uncharacteristic --- 1753, from un- (1) "not" + characteristic (adj.).

unchaste --- 1382, from un- (1) "not" + chaste.

unchecked --- 1469, from un- (1) "not" + pp. of check (v.).

unchristian --- 1555, "not professing Christianity" (of persons), from un- (1) "not" + Christian. Meaning "at variance with Christian principles" (of actions) is recorded from 1581.

unchurched --- 1681, from un- (1) "not" + churched "committed or belonging to a church" (see church). A verb, unchurch "to remove or exclude (someone) from membership in a church" is recorded from 1620.

uncial --- 1650, "pertaining to an ounce," from L. uncialis "of an inch, of an ounce," from uncia "a twelfth part" (see inch). In ref. to letters, it is attested from 1712, from L.L. litteræ unciales (Jerome), probably meaning "letters an inch high," from L. uncialis "of an inch, inch-high."

uncirculated --- 1775, from un- (1) "not" + pp. of circulate (see circulation).

uncivilized --- 1607, "barbarous," from un- (1) "not" + pp. of civilize. Uncivil in the same sense is recorded from 1553; it later came to mean "impolite" (1591).

unclassified --- 1865, from un- (1) "not" + pp. of classify.

uncle --- c.1290, from O.Fr. oncle, from L. avunculus "mother's brother," lit. "little grandfather," dim. of avus "grandfather," from PIE root *awo- "grandfather, adult male relative other than one's father" (cf. Arm. hav "grandfather," Lith. avynas "maternal uncle," O.C.S. uji "uncle," Welsh ewythr "uncle"). Replaced O.E. eam (usually maternal; paternal uncle was fædera), which represents the Gmc. form of the root (cf. Du. oom, O.H.G. oheim "maternal uncle," Ger. Ohm "uncle"). Also from Fr. are Ger., Dan., Swed. onkel. First record of Dutch uncle (and his blunt, stern, benevolent advice) is from 1838; Welsh uncle (1747) was the first cousin of one's parent. To say uncle as a sign of submission in a fight is N.Amer., attested from 1918, of uncertain signification.

Uncle Sam --- symbol of the United States of America, 1813, coined during the war with Britain as a contrast to John Bull, and no doubt suggested by the initials U.S. "[L]ater statements connecting it with different government officials of the name of Samuel appear to be unfounded" [OED]. The common figure of Uncle Sam began to appear in political cartoons c.1850. Only gradually superseded earlier Brother Jonathan (1776), largely through the popularization of the figure by cartoonist Thomas Nast. British in World War I sometimes called U.S. soldiers Sammies.

Uncle Tom --- servile black man, 1922, somewhat inaccurately in ref. to the humble, pious, but strong-willed main character in Harriet Beecher Stowe's novel, "Uncle Tom's Cabin" (1852). The image implied in the insult perhaps is more traceable to the late 19c. minstel show versions of the story, which reached a far wider audience than the book.

unclean --- O.E. unclæne, "morally impure, defiled, unfit for food," from un- (1) "not" + clean (adj.). Lit. sense of "dirty" is recorded from c.1250.

unclear --- c.1300, "not easy to understand," from un- (1) "not" + clear (adj.). Cf. M.Du. onclaer, Du. onklaar, Ger. unklar, O.N. uklarr, Dan. uklar, Swed. oklar. Of persons, in sense of "uncertain, doubtful," it is recorded from 1671. Uncleared is recorded from 1637 in ref. to debts, 1772 in ref. to land.

unclothe --- c.1300, uncloþe (trans.), from un- (2) + clothe (v.). Refl. sense is attested from 1382.

uncomfortable --- c.1425 (implied in uncomfortably) "causing discomfort," from un- (1) "not" + comfortable. Meaning "feeling discomfort, ill-at-ease" is attested from 1796.

uncommitted --- c.1381, "not delegated," from un- (1) "not" + pp. of commit. Meaning "not pledged to any particular course or party" is attested from 1814.

uncommon --- 1548, "not possessed incommon," from un- (1) "not" + common (adj.). Meaning "not commonly occurring, unusual, rare" is recorded from 1611.

uncompensated --- 1774, "not compensated by any good," from un- (1) "not" + pp. of compensate. Meaning "not recompensed" is attested from 1830.

uncompromising --- 1828, from un- (1) "not" + gerundive of compromise.

unconcerned --- c.1635, from un- (1) "not" + pp. of concern.

unconditional --- 1666, from un- (1) "not" + conditional (see condition). Unconditional surrender is attested from 1830.

unconfirmed --- 1565, "not having received the rite of confirmation," from un- (1) "not" + pp. of confirm. Meaning "not supported by further evidence" is attested from 1671.

unconscionable --- 1565, "showing no regard for conscience," from un- (1) + now rare conscionable "conscientious" (1549), from conscioned "having a conscience."

unconscious (adj.) --- 1712, "unaware, not marked by conscious thought," from un- (1) "not" + conscious. Meaning "temporarily insensible, knocked out" is recorded from 1860. In psychology, the noun the unconscious (1884) is a loan-translation of Ger. das Unbewusste. The adj. in this sense is recorded from 1912.

unconstitutional --- 1734, from un- (1) "not" + constitutional (see constitution).

uncontested --- 1678, from un- (1) "not" + pp. of contest.

uncontrolled --- 1513, from un- (1) "not" + pp. of control.

unconventional --- 1839, from un- (1) "not" + conventional (see convention). "A 19 cent. epithet for a certain type of affectation." [Weekley]

unconverted --- 1648, from un- (1) "not" + pp. of convert.

unconvinced --- 1675, from un- (1) "not" + pp. of convince. Unconvincing is recorded from 1653.

uncool --- 1953, in hipster slang, from un- (1) "not" + slang sense of cool (adj.).

uncoordinated --- 1892, from un- (1) "not" + pp. of coordinate (see coordination).

uncouple --- c.1300, from un- (2) + couple (v.). Cf. M.Du. ontcoppelen.

uncouth --- O.E. uncuð "unknown, uncertain, unfamiliar," from un- (1) "not" + cuð "known, well-known," pp. of cunnan "to know" (see can (v.)). Meaning "strange, crude, clumsy" is first recorded 1513. The compound (and the thing it describes) widespread in IE languages, cf. L. ignorantem,, O.N. ukuðr, Goth. unkunþs, Skt. ajnatah, Armenian ancanaut', Gk. agnotos, O.Ir. ingnad "unknown."

uncover --- c.1300, from un- (2) + cover (v.). Earliest use is fig.; lit. sense is attested from 1375.

uncritical --- 1659, from un- (1) "not" + critical (see critic). Cf. Du. onkritisch, Ger. unkritisch, Dan. unkritisk.

unction --- 1387, "act of anointing as a religious rite," from L. unctionem (nom. unctio) "anointing," from unctus, pp. of ungere "to anoint" (see unguent).

unctuous --- 1387, "oily," from O.Fr. unctueus, from M.L. unctuosus "greasy," from L. unctus "act of anointing," from pp. stem of unguere "to anoint" (see unguent). Fig. sense of "blandly ingratiating" is first recorded 1742, perhaps in part with a literal sense, but in part a sarcastic usage from unction in the meaning "deep spiritual feeling" (1692), such as comes from having been anointed in the rite of unction.

uncut --- 1426, "not gashed or wounded," from un- (1) "not" + cut (v.). Of books, "not having the leaves slit open" it is recorded from 1828; of plays, etc., "without excisions," it is attested from 1896.

undated --- left without indication of date, 1570, from un- (1) "not" + pp. of date (v.) "assign a date to." Cf. Ger. undatirt, Du. ongedateerd, Swed. odaterad.

undaunted --- 1442, with ref. to horses, "untamed, not broken in," from un- (1) "not" + pp. of daunt (v.). In ref. to persons, meaning "intrepid" is recorded from 1587.

undead (adj.) --- neither dead nor alive, c.1400, from un- (1) "not" + dead.

undecided --- 1540, "not decided, unsettled," from un- (1) "not" + pp. of decide (v.).

undefeated --- 1775, from un- (1) "not" + pp. of defeat (v.).

undefended --- 1564, "not defended, unprotected," from un- (1) "not" + pp. of defend (v.). Attested earlier in a now-obsolete sense of "unforbidden" (1399).

undefiled --- c.1300, undefylde, from un- (1) "not" + pp. of defile (v.). Originally of morals; sexual sense is attested from c.1450. Physical sense of "not made dirty" is from 1590.

undefined --- 1611, from un- (1) "not" + pp. of define (v.).

undelivered --- 1472, from un- (1) "not" + pp. of deliver.

undemanding --- 1939, from un- (1) "not" + gerundive of demand (v.).

undemonstrative --- 1846, "not characterized by outward expression of feelings," from un- (1) "not" + demonstrative (see demonstration).

undeniable --- 1547, from un- (1) "not" + deny + -able.

under (prep., adv.) --- O.E. under, from P.Gmc. *under- (cf. O.Fris. under, Du. onder, O.H.G. untar, Ger. unter, O.N. undir, Goth. undar), from PIE *ndhero- "lower" (cf. Skt. adhah "below;" Avestan athara- "lower;" L. infernus "lower," infra "below"). Notion of "subordination" was present in O.E. Also used in O.E. as a preposition meaning "between, among," as still in under these circumstances, etc. (though this may be an entirely separate root; see understand). Productive as a prefix in O.E. times, as in Ger. and Scand. Under the table is from 1921 in the sense of "very drunk," 1940s in sense of "illegal." To get something under (one's) belt is from 1954; to keep something under (one's) hat "secret" is from 1885; to have something under (one's) nose "in plain sight" is from 1548; to speak under (one's) breath "in a low voice" is attested from 1832. To be under (someone's) thumb "entirely controlled" is recorded from 1754.

under-achiever --- 1953, from under + achiever (see achieve). Under-achievement is recorded from 1951.

under-age (adj.) --- 1594, from under + age.

underarm --- 1816, "underhand" (in ref. to a style of throwing), from under + arm. First attested 1908 in dressmaking sense of "seams on the lower half of the arm-hole;" as a euphemism for armpit, it is attested from 1930s, popularized by advertisers.

underbelly --- 1607, from under + belly. In fig. sense of "most vulnerable part" it is recorded from Churchill's 1942 speech. Sometimes used erroneously in sense of "seamy or sordid part" of anything.

underbred --- of inferior breeding, vulgar, 1650, from under + pp. of breed (v.). Of animals, "not pure bred," attested from 1890.

underbrush --- 1775, "shrub and small trees in a forest," from under + brush (n.). Originally Amer.Eng.; cf. undergrowth, attested in the same sense from 1600.

undercarriage --- 1794, from under + carriage. Meaning "landing gear of an aircraft" is recorded from 1911.

underclass --- subordinate social class, 1918, from under + class (n.). A loan-translation of Swed. underklass.

underclassman --- sophomore or freshman, 1896, from under + class in the school form sense + man.