Waiting as an enormous row’s interrupted (7)
I believe the answer is:
abiding
'waiting' is the definition.
'an enormous row's interrupted' is the wordplay.
'an' becomes 'a'.
'enormous' becomes 'big' ('big' can be similar in meaning to 'enormous').
'row' becomes 'din' (both can mean a loud disturbance).
'interrupted' means one lot of letters goes inside another.
'big' enclosing 'din' is 'biding'.
'a'+'biding'='ABIDING'
'as' acts as a link.
(Other definitions for abiding that I've seen before include "Persisting" , "Established" , "(Of memory) enduring" , "bearing" , "Remaining or residing" .)