/ Dictionary / Index A alpha blocker: Meaning and Definition of Find definitions for: al'pha block"er Pronunciation: [key] — Pharm. Pharm. any of various substances that interfere with the action of the alpha receptors. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. alphabet soup alpha brass Related Content Daily Word Quiz: torrid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language