Down this? Any number entering hole (4)
I believe the answer is:
pint
'down this? any' is the definition.
The definition suggests a singular noun which matches the answer.
'number entering hole' is the wordplay.
'number' becomes 'n' (n can represent any number).
'entering' means one lot of letters goes inside another.
'hole' becomes 'pit' (a pit is a large hole).
'n' placed inside 'pit' is 'PINT'.
Can you help me to learn more?
(Other definitions for pint that I've seen before include "Standard measure of Guinness" , "small amount" , "One eighth of a gallon" , "Measure of the plain man's alcoholic drink" , "Liquid meassure - four gills" .)