sit in
sit-in, n. An organized, passive demonstration in which participants usu. sit (or lie) down and refuse to leave a place as a means of protesting against policies or activities. • Sit-ins originated as a communal act of protesting racial segregation. People who were discriminated against would sit in places that were prohibited to them and refuse to leave. Later the term came to refer to any group protest, as with anti–Vietnam War protests and some labor strikes. Cf. sit-down strike under STRIKE.