Few taking this could make weight correct (4,3)
I believe the answer is:
iron out
'correct' is the definition.
(to iron out is to amend or correct)
'few taking this could make weight' is the wordplay.
I cannot really understand how this works, but
'few' could be 'i' and 'i' is found in the answer.
'taking' could be 'on' (eg one taking drugs is 'on' drugs) and 'on' is found in the answer.
The remaining letters 'rout' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
(Other definitions for iron out that I've seen before include "ready for an evening exercise?" , "Settle, put right" , "Resolve" , "Get sorted" , "Flatten" .)