/nuy ag"reuh, -ag"euhr euh/ , n.
1. a river on the boundary between W New York and Ontario, Canada, flowing from Lake Erie into Lake Ontario. 34 mi. (55 km) long.
2. See Niagara Falls .
3. Fort , a fort in W New York, at the mouth of the Niagara River.
4. ( l.c. ) anything taken as resembling Niagara Falls in force and relentlessness; avalanche: a niagara of criticism.
5. Hort.
a. a variety of white grape, grown for table use.
b. the vine bearing this fruit.