Apt to make a little butter (3)
I believe the answer is:
pat
'a little butter' is the definition.
('pat' can mean a lump of butter)
'apt to make' is the wordplay.
'to make' is an anagram indicator.
'apt' is an anagram of 'PAT'.
(Other definitions for pat that I've seen before include "Hit lightly" , "Affectionate gesture - postman" , "Girl" , "Small butter piece" , "Touch lightly - bit of butter?" .)