Intimacy
来自Big Physics
early 17th century (as a noun): from late Latin intimatus, past participle of Latin intimare ‘impress, make familiar’, from intimus ‘inmost’.
wiktionary
intimate + -cy
etymonline
intimacy (n.)
1640s, from intimate (adj.) + abstract noun suffix -cy. Sense of "sexual intercourse" attested from 1670s but modern use is from newspaper euphemistic use (1882).
