Caught bishop drinking spirit? Not much! (5)
I believe the answer is:
crumb
'not much' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'caught bishop drinking spirit?' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'bishop' becomes 'B' (chess abbreviation).
'drinking' means one lot of letters goes inside another (inserted letters are consumed or drunk).
'spirit?' becomes 'rum' (alcoholic spirit).
'c'+'b'='cb'
'cb' enclosing 'rum' is 'CRUMB'.
Can you help me to learn more?
(Other definitions for crumb that I've seen before include "A tiny bit of bread" , "Tiny piece of bread or cake" , "tiny amount" , "offering a little comfort" , "Small piece of bread (or comfort!)" .)