To approve what’s removed (4)
I believe the answer is:
took
'removed' is the definition.
(I've seen this before)
'to approve' is the wordplay.
'approve' becomes 'ok' (synonyms).
'to'+'ok'='TOOK'
'what's' acts as a link.
(Other definitions for took that I've seen before include "Captured" , "Small stem of flowers" , "Gained; stole; made (notes)" , "shot" , "removed from chessboard" .)