Bank takes in stray hound (7)
I believe the answer is:
terrier
'hound' is the definition.
(thesaurus)
'bank takes in stray' is the wordplay.
'bank' becomes 'tier' (I've seen this before).
'takes in' is an insertion indicator.
'stray' becomes 'err' (synonyms).
'tier' placed around 'err' is 'TERRIER'.
(Other definitions for terrier that I've seen before include "inventory of property" , "Small lively dog, may be Scotch" , "Small, originally burrowing, dog" , "part-timer in Services" , "(Yorkshire?) dog" .)