Wife gives aid to impudent youths (6)
I believe the answer is:
whelps
'impudent youths' is the definition.
'wife gives aid to' is the wordplay.
'wife' becomes 'w'.
'gives aid to' becomes 'helps' (helping is a kind of giving aid to).
'w'+'helps'='WHELPS'
(Other definitions for whelps that I've seen before include "Young of various canines" , "Young wolves or dogs" , "Gives birth" , "puppies" , "Young dogs or pups" .)