A bit of a cat (4)
'a bit' is the definition.
(I have seen 'Tiny bit' mean 'atom' so perhaps 'bit' could also mean 'atom')
'a cat' is the wordplay.
'cat' becomes 'tom' (a tom is a male cat).
'a'+'tom'='ATOM'
'of' is the link.
(Other definitions for atom that I've seen before include "Smallest particle in an element able to take part in a chemical reaction" , "Moat (anag.)" , "Neutron and proton" , "A mighty particle, can be explosive" , "Particle; molecule" .)
This clue might be a double definition.
'a bit' is the first definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'a cat' is the second definition.
The definition and answer can be both animals as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'of' acts as a link.
Can you help me to learn more?
(Other definitions for paw that I've seen before include "Foot of clawed animal" , "Mammal's foot" , "Animal foot or hill-billy dad" , "Hand; foot" , "Animal's foot" .)