1630s, "closely acquainted, very familiar," also "inmost, intrinsic," from Late Latin intimatus, past participle of intimare "make known, announce, impress," from Latin intimus "inmost, innermost, deepest" (adj.), also used figuratively, of affections, feelings, as a noun, "close friend;" superlative of in "in" (from PIE root *en "in"). Intimate (adj.) used euphemistically in reference to women's underwear from 1904. Related: Intimately.
1530s, "make known formally;" 1580s, "suggest indirectly," back-formation from intimation (which could explain the pronunciation) or else from Late Latin intimatus, past participle of intimare "to make known." The Old French verb was intimer. Related: Intimated; intimating.
1650s, "familiar friend, person with whom one is intimate," from intimate (adj.). Sometimes 17c.-19c. in false Spanish form intimado. Latin intimus had a similar noun sense. Intimates as a commercial euphemism for "women's underwear" is from 1988.
mid-15c., "action of making known," from Old French intimation (14c.), from Late Latin intimationem (nominative intimatio) "an announcement," noun of action from past-participle stem of Latin intimare "make known, announce, impress" (see intimate (adj.)). Meaning "action of expressing by suggestion or hint, indirect imparting of information" is from 1530s.
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-14c., "intimate, very friendly, on a family footing," from Old French famelier "related; friendly," from Latin familiaris "domestic, private, belonging to a family, of a household;" also "familiar, intimate, friendly," a dissimilation of *familialis, from familia (see family).
From late 14c. as "of or pertaining to one's family." Of things, "known from long association," from late 15c. Meaning "ordinary, usual" is from 1590s.
The noun meaning "demon, evil spirit that answers one's call" is from 1580s (familiar spirit is attested from 1560s); earlier as a noun it meant "a familiar friend" (late 14c.). The Latin plural, used as a noun, meant "the slaves," also "a friend, intimate acquaintance, companion."