US city street in financially favourable situation (6)
I believe the answer is:
boston
'us city' is the definition.
(I've seen this before)
'street in financially favourable situation' is the wordplay.
'street' becomes 'st'.
'in' is an insertion indicator.
'financially favourable situation' becomes 'boon'.
'st' going into 'boon' is 'BOSTON'.
(Other definitions for boston that I've seen before include "American city famed for historic Tea Party" , "American city that once had a famous Tea Party" , "Site of rebellious tea party" , "Card game; Lincolnshire town" , "American city noted for historic Tea Party" .)