Immature pup intoxicated with beer aroma (12)

I believe the answer is:

prepubescent

'immature' is the definition.
(similar in meaning)

'pup intoxicated with beer aroma' is the wordplay.
'intoxicated with' indicates anagramming the letters.
'aroma' becomes 'scent' (synonyms).
'pup' with its letters anagrammed with 'beer' can make 'prepube'.
'prepube'+'scent'='PREPUBESCENT'

I've seen this clue in The Everyman puzzle in The Observer.

Want a hint initially instead of a full solution? Install my app