Bananas, celery and gin? A sweet-tasting liquid (9)
I believe the answer is:
glycerine
'a sweet-tasting liquid' is the definition.
I can't judge whether this defines the answer.
'bananas celery and gin?' is the wordplay.
'bananas' indicates an anagram (bananas can informally mean crazy).
'and' is a charade indicator (letters next to each other).
'celery' after 'gin' is 'gincelery'.
'gincelery' anagrammed gives 'GLYCERINE'.
Can you help me to learn more?
(Other definitions for glycerine that I've seen before include "Syrupy chemical liquid" , "Alcohol" , "Sweet stuff" , "Colourless soothing sweet viscous liquid" , "What's in bangers" .)