/ Dictionary / Index R river basin: Meaning and Definition of Find definitions for: riv'er ba"sin Pronunciation: [key] — Physical Geog. Physical Geog. the area of land drained by a river and its branches. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. riverbank grape riverbed Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language