- -in (1)[-in 词源字典]
- suffix attached to a verb, first attested 1960 with sit-in (which probably was influenced by sit-down strike); used first of protests, extended c. 1965 to any gathering.[-in etymology, -in origin, 英语词源]
- -in (2)
- chemical suffix, usually indicating a neutral substance, antibiotic, vitamin, or hormone; see -ine (2).