1. a river flowing E from NW Texas along the S boundary of Oklahoma into the Mississippi River in Louisiana. ab. 1300 mi. (2095 km) long.
2. Also called Red' Riv'er of the North'. a river flowing N along the boundary between Minnesota and North Dakota to Lake Winnipeg in S Canada. 533 mi. (860 km) long.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.