Why is the ninth month called September?
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.).