Son involved in fight returned with scrapes (5)
I believe the answer is:
rasps
'scrapes' is the definition.
(I've seen this before)
'son involved in fight returned' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'involved in' means one lot of letters goes inside another.
'fight' becomes 'spar' (sparring is a kind of fighting).
'returned' says the letters should be written in reverse.
's' placed into 'spar' is 'spsar'.
'spsar' backwards is 'RASPS'.
'with' is the link.
(Other definitions for rasps that I've seen before include "Coarse files" , "speaks hoarsely" , "Grates harshly" , "Scrapes" , "Jars" .)