/ Dictionary / Index C commission house: Meaning and Definition of Find definitions for: commis'sion house" Pronunciation: [key] a brokerage firm that buys and sells securities on commission. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. commissioner commission plan Related Content Daily Word Quiz: cosmology Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language