Definition of "meridian" []

• An imaginary great circle on the earth's surface passing through the North and South geographic poles. All points on the same meridian have the same longitude. (noun)
• Either half of such a great circle from pole to pole. (noun)
• Astronomy A great circle passing through the two poles of the celestial sphere and the zenith of a given observer. (noun)
• Mathematics A curve on a surface of revolution, formed by the intersection of the surface with a plane containing the axis of revolution. (noun)
• Mathematics A plane section of a surface of revolution containing the axis of revolution. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The first jog west of a meridian is about 225 feet, and the correction increases by about that much again for every township you move west, until you reach the next meridian."
• "The advantage of stick with 1000 time divisions per day and the Swiss meridian is that you could, in order to bootstrap the efffort, use the downloads from the Swatch website for tracking ‘hashtime’"
• "The largest meridian is 180 degrees as you ought to know very well."