- a river on the boundary between W New York and Ontario, Canada, flowing from Lake Erie into Lake Ontario. 34 miles (55 km) long.
- Niagara Falls.
- a fort in W New York, at the mouth of the Niagara River.
- anything taken as resembling Niagara Falls in force and relentlessness; avalanche: a niagara of criticism.
- Horticulture.
- a variety of white grape, grown for table use.
- the vine bearing this fruit.
- a river in NE North America, on the border between W New York State and Ontario, Canada, flowing from Lake Erie to Lake Ontario. Length: 45 km (28 miles)
- a torrent
