Confronts son during exam retakes (7)
I believe the answer is:
resists
'confronts' is the definition.
(resist can mean to face or confront)
'son during exam retakes' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'during' means one lot of letters goes inside another.
'exam retakes' becomes 'resits' (sitting an exam again).
's' going within 'resits' is 'RESISTS'.
(Other definitions for resists that I've seen before include "Defies" , "Stands up to, withstands" , "Tries to stop" , "Is hostile to" , "Fights back" .)