Swollen bananas go green — close to bad (8)
I believe the answer is:
engorged
'swollen' is the definition.
(I've seen this before)
'bananas go green close to bad' is the wordplay.
'bananas' indicates an anagram (informal term for mad).
'close to' says to take the final letters (the close/ending of).
The last letter of 'bad' is 'd'.
'go'+'green'='gogreen'
'gogreen' anagrammed gives 'engorge'.
'engorge'+'d'='ENGORGED'
(Other definitions for engorged that I've seen before include "Swollen with fluid" , "Filled to excess" , "Crammed full (of food)" .)