She introduces boy to youth leader (4)
I believe the answer is:
lady
'she introduces' is the definition.
I can't judge whether this definition defines the answer.
'boy to youth leader' is the wordplay.
'boy' becomes 'lad' (informal term for boy).
'to youth leader' becomes 'y' (I've seen this in other clues).
'lad'+'y'='LADY'
Can you help me to learn more?
(Other definitions for lady that I've seen before include "mature woman" , "Woman, maybe titled" , "See 2" , "older female" , "Woman, of refinement perhaps" .)