Puts on, perhaps (4)
I believe the answer is:
adds
'puts on perhaps' is the definition.
(putting on is a kind of adding)
This is the entire clue.
(Other definitions for adds that I've seen before include "Puts (numbers) together" , "Tots up" , "Sums, totals" , "Appends; Totals" , "Finds the sum (4)," .)