Window frame made by son, with wood (4)
I believe the answer is:
sash
'window frame' is the definition.
(thesaurus)
'son with wood' is the wordplay.
'son' becomes 's'.
'with' is a charade indicator (letters next to each other).
'wood' becomes 'ash' (I've seen this before**).
's'+'ash'='SASH'
'made by' acts as a link.
(Other definitions for sash that I've seen before include "Decorative belt" , "Ribbon as a symbol of rank" , "Item of clothing - frame for glass" , "Framework holding window panes" , "Sliding window frame" .)