ˈsit-in BrE AmE noun [countable]
a type of protest in which people refuse to leave the place where they work or study until their demands are considered or agreed to
hold/stage a sit-in
Several thousand students staged sit-ins and protest marches.
SIT-IN
Meaning of SIT-IN in English
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012