Mother's framing son's degree (7)
I believe the answer is:
masters
'degree' is the definition.
(master's degree is a kind of degree)
'mother's framing son's' is the wordplay.
'mother's' becomes 'mater's' (old-fashioned term for mother).
'framing' means one lot of letters goes inside another (inserted letters are framed by the outside letters).
'maters' enclosing 's' is 'MASTERS'.
(Other definitions for masters that I've seen before include "Boys" , "competition today" , "Higher degree" , "Could be checkers" , "Artists of consummate skill" .)