Owing to there being a terrible din outside (2,3,3)
I believe the answer is:
in the red
'owing' is the definition.
Both the answer and definition are adjectives.
Maybe they are linked in a way I don't understand?
'there being a terrible din outside' is the wordplay.
'being a terrible din' becomes 'ind' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'outside' indicates putting letters inside.
'there' going inside 'ind' is 'IN THE RED'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for in the red that I've seen before include "Indebted" , "have no credit" , "needing cash injection" , "Colourfully in debt to the bank" , "Owing money, bank account overdrawn" .)