/ Dictionary / Index R Red River: Meaning and Definition of Find definitions for: Red' Riv'er Pronunciation: [key] 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. Also calleda river flowing N along the boundary between Minnesota and North Dakota to Lake Winnipeg in S Canada. 533 mi. (860 km) long. Songka. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. red ribbon Red River War Related Content Daily Word Quiz: nonchalant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language