Teenager makes smell after beer-drinking party (10)
I believe the answer is:
adolescent
'teenager' is the definition.
('adolescent' can be a synonym of 'teenager')
'smell after beer-drinking party' is the wordplay.
'smell' becomes 'scent' (scent is a kind of smell**).
'after' means one lot of letters go next to another.
'beer' becomes 'ale' (I've seen this before).
'drinking' means one lot of letters goes inside another.
'party' becomes 'do' (do is a kind of party).
'ale' placed around 'do' is 'adole'.
'scent' after 'adole' is 'ADOLESCENT'.
'makes' is the link.
(Other definitions for adolescent that I've seen before include "Youth" , "Teenage" , "Person in child-adult transition" , "Developing" , "juvenile" .)