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