Milk or paint, possibly (5)
I believe the answer is:
pinta
'milk' is the definition.
Both the answer and definition are singular nouns.
Maybe there's an association between them I don't understand?
'paint possibly' is the wordplay.
'possibly' indicates anagramming the letters.
'paint' is an anagram of 'PINTA'.
'or' is the link.
Can you help me to learn more?
(Other definitions for pinta that I've seen before include "vessel for Columbus?" , "early delivery?" , "Bottle of milk" , "drink" , "Columbus's ship - some milk!" .)