One in cottage room has good living (5)
I believe the answer is:
being
'living' is the definition.
('be' can be a synonym of 'live')
'one in cottage room has good' is the wordplay.
I cannot really see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
'room' could be 'ben' (I have seen 'inner room' mean 'ben' so perhaps 'room' could also mean 'ben') and 'ben' is found within the leftover letters.
'good' could be 'g' (abbreviation) and 'g' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for being that I've seen before include "Existing" , "Existence" , "substance" , "Person" , "A matter of 9 in the play" .)