/sit"in'/ , n.
1. an organized passive protest, esp. against racial segregation, in which the demonstrators occupy seats prohibited to them, as in restaurants and other public places.
2. any organized protest in which a group of people peacefully occupy and refuse to leave a premises: Sixty students staged a sit-in outside the dean's office.
3. See sit-down strike .
[ 1955-60; n. use of v. phrase sit in (a place); cf. -IN ]