Male offspring (3)
'male offspring' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for sons that I've seen before include "DH Lawrence novel: __ and Lovers" , "Male offspring" .)
'male offspring' is the definition.
(son is a kind of male offspring)
This is the entire clue.
(Other definitions for son that I've seen before include "Heir" , "Express paper" , "The kind of child" , "Human offspring" , "Male scion" .)