Couple, trim (we're told) (4)
I believe the answer is:
pair
'couple' is the definition.
(synonyms)
'trim we're told' is the wordplay.
'trim' becomes 'pare' (synonyms).
'we're told' indicates a 'sounds like' (homophone) clue.
'pare' sounds like 'PAIR'.
(Other definitions for pair that I've seen before include "Twins" , "Agreement to avoid division" , "Duo" , "Brace, couple" , "Two of a similar type" .)