1630s, "closely acquainted, very familiar," from Late Latin intimatus, past participle of intimare "make known, announce, impress," from Latin intimus "inmost" (adj.), "close friend" (n.), superlative of in "in" (see in- (2)). Used euphemistically in reference to women's underwear from 1904. Related: Intimately.
"suggest indirectly," 1530s, back-formation from intimation, or else from Late Latin intimatus, past participle of intimare. Related: Intimated; intimating.
1650s, "person with whom one is intimate," from intimate (adj.).