incubation n.

Proto-Indo-European root meaning "in."

It forms all or part of: and; atoll; dysentery; embargo; embarrass; embryo; empire; employ; en- (1) "in; into;" en- (2) "near, at, in, on, within;" enclave; endo-; enema; engine; enoptomancy; enter; enteric; enteritis; entero-; entice; ento-; entrails; envoy; envy; episode; esoteric; imbroglio; immolate; immure; impede; impend; impetus; important; impostor; impresario; impromptu; in; in- (2) "into, in, on, upon;" inchoate; incite; increase; inculcate; incumbent; industry; indigence; inflict; ingenuous; ingest; inly; inmost; inn; innate; inner; innuendo; inoculate; insignia; instant; intaglio; inter-; interim; interior; intern; internal; intestine; intimate (adj.) "closely acquainted, very familiar;" intra-; intricate; intrinsic; intro-; introduce; introduction; introit; introspect; invert; mesentery.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit antara- "interior;" Greek en "in," eis "into," endon "within;" Latin in "in, into," intro "inward," intra "inside, within;" Old Irish in, Welsh yn, Old Church Slavonic on-, Old English in "in, into," inne "within, inside."

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.

1640s (transitive), "to brood upon, watch jealously" (figurative); 1721 in literal sense "to sit on (eggs) to hatch them," from Latin incubatus, past participle of incubare "to lie in or upon," also in the figurative sense "brood" (see incubation). Intransitive sense "to sit upon eggs" is from 1755. Related: Incubated; incubating.