Remove fellows attending party (4)
I believe the answer is:
Here is my best explanation:
'remove' is the definition.
(I've seen this before)
'fellows attending party' is the subsidiary indication.
'fellows' becomes 'ff'.
'attending' is a charade indicator (letters next to each other).
'party' becomes 'do' (do is a kind of party).
'ff' after 'do' is 'doff'.
(Other definitions for doff that I've seen before include "Remove (e.g. hat)", "(Of hat) remove", "Take off hat as mark of respect", "Lift (one's hat)", "Remove one's cap", "Take off (clothing) - remove (hat)" and "Remove, hat say".)