Don't allow a bachelor to have a bit of fun (3)
I believe the answer is:
ban
'don't allow' is the definition.
(I've seen this in other clues)
'a bachelor to have a bit of fun' is the wordplay.
I cannot really see how this works, but
'a' could be 'an' and 'an' is found within the answer.
'bachelor' could be 'b' (abbreviation e.g. BA=Bachelor of Arts) and 'b' is present in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ban that I've seen before include "'Forbid, prohibit (3)'" , "Hungarian governor < to forbid" , "Veto" , "Officially prohibit" , "Bar, prohibition" .)