Tramples family member (7)
I believe the answer is:
stepson
This clue is a double definition.
'tramples' is the first definition.
(I've seen this before)
'family member' is the second definition.
(son of one's spouse)
(Other definitions for stepson that I've seen before include "Subdues" , "could be issue for partner" , "Male child of spouse by earlier marriage" , "partner's sprog" , "Tramples (5,2) -- relative" .)