1. (a.) Being at, or pertaining to, midday; belonging to, or passing through, the highest point attained by the sun in his diurnal course.

2. (a.) Pertaining to the highest point or culmination; as, meridian splendor.

3. (a.) Midday; noon.

4. (a.) Hence: The highest point, as of success, prosperity, or the like; culmination.

5. (n.) A great circle of the sphere passing through the poles of the heavens and the zenith of a given place. It is crossed by the sun at midday.

6. (n.) A great circle on the surface of the earth, passing through the poles and any given place; also, the half of such a circle included between the poles.

Antarctic Zone Arctic Circle Arctic Zone Frigid Zones Lambert conformal projection Mercator projection Miller projection Torrid Zone Tropic of Cancer Tropic of Capricorn Variable Zones acmatic acme aeronautical chart apex aphelion apical apogee astronomical chart astronomical longitude atlas autumnal equinox azimuthal equidistant projection azimuthal projection brow cap capital cartographer cartography celestial chart celestial equator celestial globe celestial longitude celestial meridian chart chief chorographer chorography circle climate climatic chart climax clime cloud nine colures conic projection consummate contour line contour map crest crown culmen culmination cylindrical projection ecliptic edge eight bells equator equinoctial equinoctial circle equinoctial colure equinox extreme limit extremity galactic longitude general reference map geocentric longitude geodetic longitude globe gnomonic projection graphic scale great circle grid line hachure head headmost heaven heavens height heliocentric longitude heliographic chart high noon highest highest pitch highest point horse latitudes hydrographic chart index isoline latitude layer tint legend limit longitude longitude in arc map map maker map projection mapper maximal maximum meridiem meridional midday mountaintop ne plus ultra no place higher noon noonday nooning noonish noonlight noonlit noontide noontime orbit overmost parallel paramount peak perigee perihelion period photogrammetrist photogrammetry photomap phototopography physical map pinnacle pitch point pole political map polyconic projection preeminent prime meridian projection relief map representative fraction ridge road map roaring forties scale seventh heaven sinusoidal projection sky small circle solstitial colure special map spire subtropics summit summital supreme terrain map terrestrial globe the line thematic map tip tip-top top topmost topographer topographic chart topography trajectory transportation map tropic tropics ultimate upmost upper extremity uppermost utmost vernal equinox vertex vertical very top weather chart weather map zenith zenithal zodiac zone