Being more chubby is almost a game (7)
I believe the answer is:
rounder
'being more chubby' is the definition.
Both the answer and definition are comparative adjectives. Maybe they are linked in a way I don't understand?
'almost a game' is the wordplay.
'almost' means to remove the last letter (almost the whole word is kept).
'a game' becomes 'rounders' (rounders is a kind of game).
'rounders' with its final letter removed is 'ROUNDER'.
'is' is the link.
Can you help me to learn more?
(Other definitions for rounder that I've seen before include "complete circuit in a game" , "More circular" , "Or under (anag.)" , "More rotund" , "Score in bat and ball game" .)