Definition of "equator" []

• The imaginary great circle around the earth's surface, equidistant from the poles and perpendicular to the earth's axis of rotation. It divides the earth into the Northern Hemisphere and the Southern Hemisphere. (noun)
• A similar great circle drawn on the surface of a celestial body at right angles to the axis of rotation. (noun)
• The celestial equator. (noun)
• A circle that divides a sphere or other surface into congruent parts. (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.

• "It's due south of Hawaii, as far south of the equator is as Hawaii is north of the equator."
• "You may know that the entire world, south of the equator, is one huge nuclear weapon free zone (NWFZ)."
• "Its radius at the equator is slightly bigger than at its poles."