Locating endless protest (3,2)
I believe the answer is:
sit in
'protest' is the definition.
(sit-in is a type of non-violent protest)
'locating endless' is the wordplay.
'locating' becomes 'siting' ('site' can be a synonym of 'locate').
'endless' means to remove the last letter.
'siting' with its last letter removed is 'SIT-IN'.
(Other definitions for sit in that I've seen before include "form of protest" , "demonstration" , "Act as a substitute for" , "act as someone's deputy" .)