/ Dictionary / Index A Alpha Centauri: Meaning and Definition of Find definitions for: Al'pha Centau'ri Pronunciation: [key] a triple-star system that is the brightest celestial object in the constellation Centaurus. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. alpha brass alpha decay Related Content Daily Word Quiz: jugular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language