Solidly built porter (5)
I believe the answer is:
stout
I believe this is a double definition.
'solidly built' is the first definition.
(I've seen this in another clue)
'porter' is the second definition.
(synonyms)
(Other definitions for stout that I've seen before include "Heavily built; drink" , "of above-average weight" , "Round" , "Bulky" , "Fat; dependable" .)