Act of civil disobedience (3-2)
I believe the answer is:
sit-in
'act of civil disobedience' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sit-in that I've seen before include "Occupation demo" , "Protest demo" , "Factory protest" , "Passive occupation of a premises" , "Seated protest" .)