/ Dictionary / Index G galactic longitude: Meaning and Definition of Find definitions for: galac'tic lon'gitude Pronunciation: [key] — Astron. Astron. the angular distance in degrees measured eastward in the galactic plane from a radius drawn from the earth as center to the constellation Sagittarius. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. galactic latitude galactic nebula Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language