from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Angular distance on the earth's surface, measured east or west from the Prime Meridian at Greenwich, England, to the meridian passing through a position, expressed in degrees (or hours), minutes, and seconds.
  • noun Celestial longitude.

from The Century Dictionary.

  • noun Length; measure along the longest line.
  • noun In geography, the angle at the pole contained between two meridians, one of which, called the first or prime meridian, passes through some conventional point from which the angle is measured.
  • noun In astronomy, the arc of the ecliptic measured eastward from the vernal equinoctial point to the foot of the circle of latitude drawn through the object, as a star or other point on the sphere whose position is in question. See circle of latitudes, under circle.

from the GNU version of the Collaborative International Dictionary of English.

  • noun Length; measure or distance along the longest line; -- distinguished from breadth or thickness; ; rare now, except in a humorous sense.
  • noun (Geog.) 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
  • noun (Astron.) 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.
  • noun (Astron.) the longitude of a heavenly body as seen from the earth.
  • noun the longitude of a heavenly body, as seen from the sun's center.
  • noun certain stars whose position is known, and the data in regard to which are used in observations for finding the longitude, as by lunar distances.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun Angular distance measured west or east of the prime meridian.
  • noun Any imaginary line perpendicular to the equator and part of a great circle passing through the North Pole and South Pole.
  • noun archaic Length.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun the angular distance between a point on any meridian and the prime meridian at Greenwich


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English, length, a measured length, from Old French, from Latin longitūdō, longitūdin-, from longus, long; see del- in Indo-European roots.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Middle English, from Latin longitūdō ("length, a measured length"), from longus ("long").


Help support Wordnik (and make this page ad-free) by adopting the word longitude.



Log in or sign up to get involved in the conversation. It's quick and easy.

  • Her longitudes are wickedness.

    Her anvil is corporeal sorrow.

    Raymond Farr, on the communal As/Is

    December 21, 2006