noun lon·gi·tude \ ˈlän-jə-ˌtüd , -ˌtyüd , British also ˈläŋ-gə- \
Updated on: 12 Nov 2017

Definition of longitude

1 a :angular distance measured on a great circle of reference from the intersection of the adopted zero meridian with this reference circle to the similar intersection of the meridian passing through the object
b :the arc or portion of the earth's equator intersected between the meridian of a given place and the prime meridian and expressed either in degrees or in time
2 archaic :long duration

Examples of longitude in a Sentence

  1. a map of the world showing lines of latitude and longitude

  2. calculating the longitudes of different places

  3. The regions are on roughly the same longitude.

Recent Examples of longitude from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'longitude.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Did You Know?

The imaginary (but very important) lines of longitude run from the North Pole to the South Pole. Each is identified by the number of degrees it lies east or west of the so-called prime meridian in Greenwich, England (part of London). A circle is divided into 360°; so, for example, the longitude of the Egyptian city of Cairo is about 31°E—that is, about 31° east of London. The "long" sense of the root may be easier to see in some uses of the adjective longitudinal: A longitudinal study is a research study that follows its subjects over many long years, and a longitudinal engine is one that drives a crankshaft that runs lengthwise under a vehicle (as in rear-wheel-drive cars) rather than crosswise.

Illustration of longitude

Origin and Etymology of longitude

Middle English, from Latin longitudin-, longitudo, from longus

LONGITUDE Defined for English Language Learners



Definition of longitude for English Language Learners

  • : distance measured in degrees east or west from an imaginary line (called the prime meridian) that goes from the North Pole to the South Pole and that passes through Greenwich, England

  • : an imaginary line that circles the Earth at a particular longitude

LONGITUDE Defined for Kids


noun lon·gi·tude \ ˈlän-jə-ˌtüd , -ˌtyüd \

Definition of longitude for Students

:distance measured in degrees east or west of an imaginary line that runs from the north pole to the south pole and passes through Greenwich, England

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