A strong porter (5)
I believe the answer is:
stout
This clue is a double definition.
'a strong' is the first definition.
(thesaurus)
'porter' is the second definition.
(synonyms)
(Other definitions for stout that I've seen before include "Fat; dependable" , "Dark beer for the rather fat" , "Strong; drink" , "Rather fat, stocky" , "Beer with malt" .)