Corpulent plus (5)
I believe the answer is:
obese
'corpulent plus' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for obese that I've seen before include "Stout" , "Extremely overweight" , "Roly-poly" , "Falstaffian" , "getting well-upholstered" .)