He's no peasant! (4)
I believe the answer is:
poet
'peasant' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'he's no' is the wordplay.
I cannot really understand how this works, but
'no' could be 'o' (resembles 0 - 'no' can mean 'zero') and 'o' is located in the answer.
The remaining letters 'pet' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for poet that I've seen before include "Eg, Keats or Auden" , "Burns, for example" , "Writer such as Ogden Nash" , "Pound, say" , "Bard" .)