Very little matter for a cat (4)
I believe the answer is:
atom
'very little' is the definition.
'atom' can be an answer for 'little' (thesaurus). I'm not certain of the 'very' bit.
'matter for a cat' is the wordplay.
'matter' becomes 'A' (A is an example).
'for' means one lot of letters go next to another.
'a cat' becomes 'tom' (a tom is a male cat).
'a'+'tom'='ATOM'
Can you help me to learn more?
(Other definitions for atom that I've seen before include "A wee bit" , "A mighty particle, makes huge explosion" , "Piece of matter in moat" , "A tiny particle of matter with a big bang" , "Particle; molecule" .)