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 (such as U-Haul , attested from 1951).

The substitution of Middle English -o- for Old English -u- before -m- , -n- , or -r- was a French scribal habit before minims to avoid misreading the letters in the old style handwriting, which jammed them together. The practice transformed some , come , monk , tongue , worm .

German or Austrian subway system, 1938 (originally in reference to Berlin), from German U-bahn , short for Untergrund-bahn , literally "underground railway."

"whereness," 1670s, from Modern Latin ubietas , from Latin ubi "where" (see ubi ).

"place, location, position," 1610s, common in English c. 1640-1740, from Latin ubi "where?, in which place, in what place," relative pronominal adverb of place, ultimately from PIE *kwo-bhi- (source also of Sanskrit kuha , Old Church Slavonic kude "where"), locative case of pronominal root *kwo- . Ubi sunt , literally "where are" (1914), in reference to lamentations for the mutability of things is from a phrase used in certain Medieval Latin Christian works.

"omnipresence," 1570s, from Modern Latin ubiquitas , from Latin ubique "everywhere," from ubi "where" (see ubi ) + - que "and," also "any, also, ever," as a suffix giving universal meaning to the word it is attached to, from PIE root *kwe "and, -ever" (source also of Hittite -kku "now, even, and;" Sanskrit -ca , Avestan -ca "and, also, if;" Greek -te "and;" Gothic -uh "and, also," nih "if not").

Originally a Lutheran theological position maintaining the omnipresence of Christ.

"being, existing, or turning up everywhere," 1800, from ubiquity + -ous . The earlier word was ubiquitary (c. 1600), from Modern Latin ubiquitarius , from ubique (see ubiquity ). Related: Ubiquitously ; ubiquitousness .

1916 (said to have been in use from 1913), partial translation of German U-Boot , short for Unterseeboot , literally "undersea boat."

Old English udder "milk gland of a cow, goat, etc.," from Proto-Germanic *udr- (source also of Old Frisian uder , Middle Dutch uyder , Dutch uijer , Old High German utar , German Euter , and, with unexplained change of consonant, Old Norse jugr ), from PIE *eue-dh-r "udder" (source also of Sanskrit udhar , Greek outhar , Latin uber "udder, breast").

1953, abbreviation of Unidentified Flying Object , which is attested from 1950.

1959, from UFO + -logy .