/ Dictionary / Index A astronomical triangle: Meaning and Definition of Find definitions for: as'tronom'ical tri'angle Pronunciation: [key] the spherical triangle formed by the great circles connecting a celestial object, the zenith, and the celestial pole. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. astronomical telescope astronomical twilight Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language