What is Nigerien?
Nigerien definition and meaning on Dictionary terms:
a republic in NW Africa: formerly part of French West Africa. 458,976 sq. mi. (1,188,748 sq. km). Capital: Niamey.
a river in W Africa, rising in S Guinea, flowing NE through Mali, and then SE through Nigeria into the Gulf of Guinea. 2600 miles (4185 km) long.