Definition

1. Adjective:

   • Relating to an equinox: Pertaining to the time when the sun crosses the celestial equator, making day and night of approximately equal length everywhere on Earth.
   • Relating to the vicinity of the equator: Concerning the region near the Earth's equator.

2. Noun:

   • The celestial equator: The great circle on the celestial sphere that is midway between the celestial poles, representing the projection of Earth's equator into space.

Examples of Usage

• Adjective:

  • The equinoctial storms are known for their intensity. (The storms occurring around the equinox are known for their intensity.)
  • The ship sailed through equinoctial regions. (The ship sailed through regions near the equator.)

• Noun:

  • The sun appears to cross the equinoctial twice a year. (The sun appears to cross the celestial equator twice a year.)

Advanced Usage

• "Equinoctial point": Either of the two points on the celestial sphere where the celestial equator intersects the ecliptic (the sun's apparent path). These are the vernal and autumnal equinoxes.

  • The vernal equinox is also known as the First Point of Aries, an equinoctial point.

• "Equinoctial line": Another term for the celestial equator.

  • Stars near the equinoctial line are visible from both hemispheres.

Variants and Related Words

• Equinox (n): Either of the two times in the year (around March 20 and September 22) when the sun crosses the celestial equator, resulting in nearly equal day and night.

  • The spring equinox marks the beginning of autumn in the Southern Hemisphere.

• Equinoctially (adv): In an equinoctial manner; pertaining to the equinox or equator.

  • The event is scheduled equinoctially, to coincide with the March equinox.

Synonyms

• Celestial equator (n): A direct synonym for the noun form.
• Equatorial (adj): Similar in meaning when referring to the region of the equator (though "equatorial" is more common and broader).

Related Phrases

• Equinoctial gales: Storms traditionally associated with the time of the equinoxes.

  • Sailors once feared the equinoctial gales.

• Equinoctial year: A tropical year, measured from one vernal equinox to the next.

  • An equinoctial year is about 365.2422 days long.

Adjective

1. relating to an equinox (when the lengths of night and day are equal)
2. relating to the vicinity of the equator

Noun

1. the great circle on the celestial sphere midway between the celestial poles