- sit-in
[sit-in 词源字典]
- 1936, in reference to session musicians; 1937, in reference to union action; 1941, in reference to student protests. From the verbal phrase; see sit (v.) + in (adv.). To sit in is attested from 1868 in the sense "attend, be present;" from 1919 specifically as "attend as an observer."[sit-in etymology, sit-in origin, 英语词源]