/ Dictionary / Index U Upper Chinook: Meaning and Definition of Find definitions for: Up'per Chinook' Pronunciation: [key] a Chinookan language of the Columbia River valley from the Deschutes River to the estuary. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. upper chamber upper class Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language