Trap broken a bit (4)
I believe the answer is:
part
'a bit' is the definition.
(I've seen this before)
'trap broken' is the wordplay.
'broken' indicates an anagram.
'trap' with letters rearranged gives 'PART'.
(Other definitions for part that I've seen before include "Some; break" , "unemployed actor hopes for" , "Piece, segment" , "goodbye" , "Divide; role" .)