1. (n.) Length; measure or distance along the longest line; -- distinguished from breadth or thickness; as, the longitude of a room; rare now, except in a humorous sense.

2. (n.) The arc or portion of the equator intersected between the meridian of a given place and the meridian of some other place from which longitude is reckoned, as from Greenwich, England, or sometimes from the capital of a country, as from Washington or Paris. The longitude of a place is expressed either in degrees or in time; as, that of New York is 74 or 4 h. 56 min. west of Greenwich.

3. (n.) The distance in degrees, reckoned from the vernal equinox, on the ecliptic, to a circle at right angles to the ecliptic passing through the heavenly body whose longitude is designated; as, the longitude of Capella is 79.

Antarctic Zone Arctic Circle Arctic Zone Cartesian coordinates Frigid Zones Lambert conformal projection Mercator projection Miller projection Torrid Zone Tropic of Cancer Tropic of Capricorn Variable Zones abscissa aeronautical chart altitude aphelion apogee astronomical chart astronomical longitude atlas autumnal equinox azimuth azimuthal equidistant projection azimuthal projection cartographer cartography celestial chart celestial equator celestial globe celestial longitude celestial meridian chart chorographer chorography circle climate climatic chart clime colures conic projection contour line contour map coordinates cylindrical coordinates cylindrical projection declination distance ecliptic equator equator coordinates equinoctial equinoctial circle equinoctial colure equinox extension extent galactic longitude general reference map geocentric longitude geodetic longitude globe gnomonic projection graphic scale great circle grid line hachure heliocentric longitude heliographic chart horse latitudes hydrographic chart index infinity isoline latitude layer tint legend length lengthiness linear measures long time longitude in arc longness map map maker map projection mapper measure meridian mileage orbit ordinate overall length parallel perigee perihelion period perpetuity photogrammetrist photogrammetry photomap phototopography physical map polar coordinates political map polyconic projection prime meridian projection reach relief map representative fraction right ascension road map roaring forties scale sinusoidal projection small circle solstitial colure span special map stretch subtropics terrain map terrestrial globe the line thematic map topographer topographic chart topography trajectory transportation map tropic tropics vernal equinox weather chart weather map yardage zodiac zone