Broken — though broken by son (4)
I believe the answer is:
bust
'broken' is the definition.
(I've seen this before)
'though broken by son' is the wordplay.
'though' becomes 'but' (**).
'broken by' means one lot of letters goes inside another.
'son' becomes 's'.
'but' placed around 's' is 'BUST'.
(Other definitions for bust that I've seen before include "Houdon's Voltaire" , "Sculpture of head and shoulders" , "Chest; bankrupt" , "Raid - boobs" , "item of statuary" .)