Very overweight (5)
I believe the answer is:
obese
'very overweight' 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 "Extremely overweight" , "Carrying far too much weight" , "Falstaffian" , "Morbidly overweight" , "Extremely fat" .)