Man, not married, drinking this in boozer? (3)
I believe the answer is:
ale
'drinking this in boozer?' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'man not married' is the wordplay.
'man' becomes 'male'.
'not' suggests deleting specific letters.
'married' becomes 'm' (abbreviation, e.g. in genealogy).
'male' with 'm' removed is 'ALE'.
Can you help me to learn more?
(Other definitions for ale that I've seen before include "festival" , "brewing?" , "Light-coloured beer" , "Grog" , "One beer" .)