Definitions of equator

1. an imaginary line around the Earth forming the great circle that is equidistant from the north and south poles; " the equator is the boundary between the northern and southern hemispheres"

2. The great circle of the celestial sphere, coincident with the plane of the earth's equator; -- so called because when the sun is in it, the days and nights are of equal length; hence called also the equinoctial, and on maps, globes, etc., the equinoctial line.

3. The imaginary circle which passes round the middle of the earth, everywhere equally distant from the poles and divides it into two hemispheres or parts; a similar line dividing the sphere of the sky in two.

4. ( geog.) A great circle passing round the middle of the globe, and dividing it into two equal parts: ( astr.) the equinoctial.

5. Great circle of the globe, midway between the poles.

6. A great circle of a globe, as the earth, midway between the poles.

7. A great circle of the terrestrial globe, equally distant from the two poles, and dividing the earth into two hemispheres, the north and the south; a great circle in the heavens marked out by the extension to them of the plane of the earth's equator.

8. Equatorially.

9. Equatorial.