procumbent adj.

word-forming element meaning "forward, forth, toward the front" (as in proclaim, proceed); "beforehand, in advance" (prohibit, provide); "taking care of" (procure); "in place of, on behalf of" (proconsul, pronoun); from Latin pro (adv., prep.) "on behalf of, in place of, before, for, in exchange for, just as," which also was used as a first element in compounds and had a collateral form por-.

Also in some cases from cognate Greek pro "before, in front of, sooner," which also was used in Greek as a prefix (as in problem). Both the Latin and Greek words are from PIE *pro- (source also of Sanskrit pra- "before, forward, forth;" Gothic faura "before," Old English fore "before, for, on account of," fram "forward, from;" Old Irish roar "enough"), extended form of root *per- (1) "forward," hence "in front of, before, toward, near," etc.

The common modern sense of "in favor of, favoring" (pro-independence, pro-fluoridation, pro-Soviet, etc.) was not in classical Latin and is attested in English from early 19c.

mid-15c., "bedroom, bedchamber," from Latin cubiculum "bedroom," from cubare "to lie down," which is perhaps from a PIE *kub-, with cognates in Middle Welsh kyscu, Middle Cornish koska, Middle Breton cousquet "to sleep," but de Vaan regards the PIE origin of the Latin word as "uncertain." Compare cubit.

Obsolete from 16c. but revived by 1858 for "dormitory sleeping compartment," especially in an English public school. The sense of "any partitioned space" (such as a library carrel or, later, office work station) is attested by 1926. Related: Cubicular.