Falls in this river? (7)
I believe the answer is:
niagara
I believe this is a double definition.
'falls' is the first definition.
(Niagara Falls)
'this river?' is the second definition.
(I've seen this before)
'in' acts as a link.
(Other definitions for niagara that I've seen before include "North American waterfall" , "Canadian waterfall" , "1953 Marilyn Monroe film noir thriller" , "It falls in North America" , "Great waterfalls on Canadian-US border" .)