One who won't stand any nonsense at the meeting? (8)
I believe the answer is:
chairman
'one who won't stand any nonsense at the meeting?' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'one' is the wordplay.
I cannot really see how this works, but
'one' could be 'an' (an apple is one apple) and 'an' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for chairman that I've seen before include "Person in charge" , "man in charge" , "Presiding official" , "Head of the board" , "Committee leader" .)