Definition

1. Noun:
   • A circle dividing a sphere or other surface into two usually equal and symmetrical parts: In geometry, the "equator" is the great circle of a sphere that lies in a plane perpendicular to its axis of rotation, dividing it into two equal hemispheres.
   • An imaginary line around the Earth forming the great circle that is equidistant from the north and south poles: In geography, the "equator" is the line of 0 degrees latitude, encircling the Earth midway between the North and South Poles.
   • The boundary between the northern and southern hemispheres: The "equator" serves as the dividing line for Earth's Northern and Southern Hemispheres.

Usage Examples

• Noun:
  • The Earth's equator is approximately 40,075 kilometers long.
  • Countries located on the equator typically have a tropical climate.
  • In the model, the equator was clearly marked with a red line.

Advanced Usage

• "Celestial equator": The great circle on the celestial sphere, in the same plane as the Earth's equator.

  • Astronomers use the celestial equator as a reference point for mapping stars.

• "Magnetic equator": A line on the Earth's surface where the magnetic field is horizontal.

  • The compass needle points true north more accurately near the magnetic equator.

Variants and Related Words

• Equatorial (adj): Of, relating to, or located at the equator.
  • The equatorial region is known for its dense rainforests.

Synonyms

• Midline: A median line, especially in a geometric context.
• Great circle: The largest possible circle that can be drawn on a sphere.

Related Phrases

• "Cross the equator": To travel from one hemisphere to the other by passing over the equator.
  • The sailors held a ceremony when their ship crossed the equator.

Related Idioms

• "The heat is on at the equator": (Figurative) Used to describe a situation of intense pressure or activity, alluding to the constant heat at the equatorial region.
  • With the project deadline tomorrow, the heat is really on at the equator in our office.

Noun

1. a circle dividing a sphere or other surface into two usually equal and symmetrical parts
2. 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