Online Etymology Dictionary

-ule: suffix meaning "small, little" (capsule, module, etc.), from Fr. -ule, from L. diminutive suffix -ulus (fem. -ula, neut. -ulum).
-ulent: from L. adj. suffix -ulentus "full of."
-ure: suffix forming abstract nouns of action, from O.Fr. -ure, from L. -ura.
u: for historical evolution, see V. Used punningly for you by 1588 ["Love's Labour's Lost," V.i.60], not long after the pronunciation shift that made the vowel a homonym of the pronoun. As a simple shorthand (without intentional word-play), it is recorded from 1862. Common in business abbreviations since 1923 (e.g. U-Haul, attested from 1951).
U-bahn: Ger. or Austrian subway system, 1938 (originally in ref. to Berlin), from Ger. U-bahn, short for Untergrund-bahn, lit. "underground railway."
U-boat: 1916 (said to have been in use from 1913), partial translation of Ger. U-boot, short for Unterseeboot, lit. "undersea boat."
U-turn: 1934, from u + turn (n.). So called in ref. to the shape of the path described.
U.K.: abbreviation for United Kingdom, attested from 1892.
U.N.: abbreviation for United Nations, attested from 1946.
U.S.: abbreviation for United States, attested from 1834.
ubi: "place, location, position," 1614, common in Eng. c.1640-1740. from L. ubi "where," ult. from PIE *kwo-bhi- (cf. Skt. kuha, O.C.S. kude "where"), locative case of pronomial base *kwo-. Ubi sunt, lit. "where are" (1914), in ref. to lamentations for the mutability of things is from a phrase used in certain M.L. Christian works.
ubiquitous: "turning up everywhere," 1837, from ubiquity + -ous. The earlier word was ubiquitary (1580s), from Mod.L. ubiquitarius, from ubique. Related: Ubiquitously.
ubiquity: 1579, from M.Fr. ubiquité (17c.), from L. ubique "everywhere," from ubi "where" (see ubi) + que "any, also, ever," a suffix that can give universal meaning to the word it is attached to. Originally a Lutheran theological position maintaining the omnipresence of Christ. Ubiquitous in the sense of "turning up everywhere" is first recorded 1837, originally a jocular extension of the theological word.
udder: O.E. udder "milk gland of a cow, goat, etc.," from P.Gmc. *udr- (cf. O.Fris., M.Du. uder, O.H.G. utar, Ger. Euter, and, with unexplained change of consonant, O.N. jugr), from PIE *udhr- (cf. Skt. udhar, Gk. outhar, L. uber "udder").
UFO: 1953, abbreviation of Unidentified Flying Object, which is attested from 1950. Ufology is first attested 1959.
Ugaritic: 1936, "pertaining to Ugarit," ancient city of northern Syria, and esp. to the language first discovered there 1929 by Claude Schaeffer, from Ugarit, which probably is ult. from Sumerian ugaru "field."
ugh: 1765, imitative of the sound of a cough; as an interjection of disgust, recorded from 1837.
ugly: mid-13c., uglike "frightful or horrible in appearance," from O.N. uggligr "dreadful, fearful," from uggr "fear, apprehension, dread" (perhaps related to agg "strife, hate") + -ligr "-like." Meaning softened to "very unpleasant to look at" late 14c. Extended sense of "morally offensive" is attested from c.1300; that of "ill-tempered" is from 1680s. Among words for this concept, ugly is unusual in being formed from a root for "fear, dread." More common is a compound meaning "ill-shaped" (e.g. Gk. dyseides, L. deformis, Ir. dochrud, Skt. ku-rupa). Another Gmc. group has a root sense of "hate, sorrow" (see loath). Verb uglify is attested from 1570s. Ugly duckling (1877) is from the story by Hans Christian Andersen, first translated from Danish to English 1846. Ugly American "U.S. citizen who behaves offensively abroad" is first recorded 1958 as a book title.
uh: inarticulate sound, attested from 1605; uh-huh, spoken affirmative (often ironic or non-committal) is recorded from 1904; negative uh-uh is attested from 1924.
UHF: 1937, abbreviation of ultra-high frequency (1932) in ref. to radio frequencies in the range of 300 to 3,000 megahertz.
uhlan: "cavalryman," 1753, from Ger. Uhlan, from Pol. ulan "a lancer," from Turk. oghlan "a youth." For sense evolution, cf. infantry.
ukase: 1729, "decree issued by a Russian emperor," from Rus. ukaz "edict," from ukazat' "to show, decree," from O.C.S. ukazati, from u-, intens. prefix, + kazati "to show, order," which is related to the first element of Casimir.
Ukraine: from Rus. Ukraina, lit. "border, frontier," from u- "at" + krai "edge."
ukulele: 1896, from Hawaiian 'ukulele, lit. "leaping flea," from 'uku "louse, flea" + lele "to fly, jump, leap." So called from the rapid motion of the fingers in playing it. It developed from a Port. instrument introduced to the islands c.1879. Abbreviated form uke is attested from 1915.
ulcer: c.1400, from O.Fr. ulcere, from V.L. ulcerem, from L. ulcus (gen. ulceris) "ulcer," from PIE base *elk-es- "wound" (cf. Gk. elkos).
ulema: "scholars of Muslim religious law," 1688, from Arabic 'ulema "learned men, scholars," pl. of 'alim "learned," from 'alama "to know."
ullage: "amount by which a cask or bottle falls short of being full," late 15c., from Anglo-Fr. ulliage (early 14c.), Anglo-L. oliagium (late 13c.), O.Fr. ouillage, from ouiller "to fill up (a barrel) to the bung," lit. "to fill to the eye," from ueil "eye," from L. ochulus.
ulna: inner bone of the forearm, 1540s, from L., lit. "elbow," related to O.E. eln (see elbow).
Ulrich: masc. proper name, from Ger., from O.H.G. Uodalrich, lit. "of a rich home," from uodal "home, nobolity" (related to O.E. æðele "noble," O.N. oðal "home").
Ulster: northernmost of the four provinces of Ireland, 14c., from Anglo-Fr. Ulvestre (early 13c.), Anglo-L. Ulvestera (c.1200), corresponding to O.N. Ulfastir, probably from Ir. Ulaidh "men of Ulster" + suffix also found in Leinster, Munster, and perhaps representing Ir. tir "land."
ult.: see ultimo.
ulterior: 1646, from L. ulterior "more distant, further," comparative of *ulter "beyond" (see ultra). The sense in ulterior motives is first attested 1735.
ultimate: 1654, from L.L. ultimatus, pp. of ultimare "to be final, come to an end," from ultimus "last, final," superlative of *ulter "beyond" (see ultra). Ultimate Frisbee is attested from 1972.
ultimatum: 1731, from Mod.L., from M.L. adj. ultimatum "last possible, final," from L. ultimatum, neut. of ultimatus (see ultimate). Hamilton and others use the L. plural ultimata. In slang c.1820s, ultimatum was used for "the buttocks."
ultimo: "in the month preceding the present," 1616, common in abbreviated form ult. in 18c.-19c. correspondence and newspapers, from L. ultimo (mense) "of last (month)," abl. sing. masc. of ultimus "last" (see ultimate). Earlier it was used in the sense of "on the last day of the month specified" (1582).
ultra-: prefix meaning "beyond" (ultraviolet) or "extremely" (ultramodern), from L. ultra- from ultra (adv. and prep.) "beyond, on the further side," from PIE *al- "beyond." In common use from early 19c., it appears to have arisen from Fr. political designations. As its own word, a noun meaning "extremist" of various stripes, it is first recorded 1817, from Fr. ultra, shortening of ultra-royaliste "extreme royalist."
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," 1540s, 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 1690s 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.