At home, allow a flue (5)
I believe the answer is:
inlet
'a flue' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'at home allow' is the wordplay.
'at home' becomes 'in' ('I'm in' can mean 'I'm at home').
'allow' becomes 'let' (synonyms).
'in'+'let'='INLET'
Can you help me to learn more?
(Other definitions for inlet that I've seen before include "Strip of water extending from sea into land" , "Means of entry" , "Small opening of coastline" , "Place of entry" , "bit of a lake here?" .)