"place, location, position," 1610s, 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-.

According to OED (1989) common in English c. 1640-1740. Also in classical phrases used in English, such as 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.

Mais où sont les neiges d'antan? [Villon]

"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.

also *kwi-, Proto-Indo-European root, stem of relative and interrogative pronouns.

It might form all or part of: cheese (n.2) "a big thing;" cue (n.1) "stage direction;" either; hidalgo; how; kickshaw; neither; neuter; qua; quality; quandary; quantity; quasar; quasi; quasi-; query; quibble; quiddity; quidnunc; quip; quodlibet; quondam; quorum; quote; quotidian; quotient; ubi; ubiquity; what; when; whence; where; whether; which; whither; who; whoever; whom; whose; why.

It might also be the source of: Sanskrit kah "who, which;" Avestan ko, Hittite kuish "who;" Latin quis/quid "in what respect, to what extent; how, why," qua "where, which way," qui/quae/quod "who, which;" Lithuanian kas "who;" Old Church Slavonic kuto, Russian kto "who;" Old Irish ce, Welsh pwy "who;" Old English hwa, hwæt, hwær, etc.

word-forming element meaning usually "one half more" than the indicated unit, from Latin sesqui-, sesque- "one and a half; one-half more," contraction of *semis-que- "a half in addition," from *semis "a half" (see semi-) + -que "and" (from PIE root *kwe "and, -ever," for which see ubiquity). Latin semi- had a tendency to get partly swallowed in compounds; compare these derivatives listed in de Vaan: selibra "half a libra," semodius "half a modius," sestertius "having the value of two-and-a-half" (as a noun, the name of a silver Roman coin, short for sestertius nummus), contracted from *semistertius; simbella "coin worth half a libella;" sincipitis "a half-head."