Funds; letter (7)
I believe the answer is:
capital
I believe this is a double definition.
'funds' is the first definition.
(I've seen this before)
'letter' is the second definition.
(thesaurus)
(Other definitions for capital that I've seen before include "It's terrific in the big city" , "Money available to produce interest" , "It's excellent in the big city" , "source of profit" , "Finances" .)