Chap’s not at liberty to accept unknown supplier of sugar or butter (9)
I believe the answer is:
sycophant
'butter' 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?
'chap's not at liberty to accept unknown supplier of sugar' is the wordplay.
I cannot really see how this works, but
'not' could be 'nt' (synonyms) and 'nt' is present in the answer.
'unknown' could be 'y' (algebra) and 'y' is found in the answer.
'of' could be 'o' and 'o' is found in the answer.
an anagram of 'chap' is 'cpha' which is located in the remaining letters.
A single letter 's' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'or' is the link.
Can you help me to learn more?
(Other definitions for sycophant that I've seen before include "obsequious one" , "Creep" , "Crawler, toady" , "Servile flatterer" , "Austen's Mr Collins?" .)