/ Dictionary / Index M meridian: Meaning and Definition of Find definitions for: me•rid•i•an Pronunciation: (mu-rid'ē-un), [key] — n. a great circle of the earth passing through the poles and any given point on the earth's surface. the half of such a circle included between the poles. the great circle of the celestial sphere that passes through its poles and the observer's zenith. a point or period of highest development, greatest prosperity, or the like. (in acupuncture) any of the pathways in the body along which vital energy flows. —adj. of or pertaining to a meridian. of or pertaining to midday or noon: the meridian hour. of or indicating a period of greatest prosperity, splendor, success, etc. Me•rid•i•an Pronunciation: (mu-rid'ē-un), [key] — n. a city in E Mississippi. 46,577. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: meridian (Thesaurus) Meriden meridian angle Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language