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Webster 1913 Edition


Equinoctial

Eˊqui-noc′tial

,
Adj.
[L.
aequinoctials
, fr.
aequinoctium
equinox: cf. F.
équinoxial
. See
Equinox
.]
1.
Pertaining to an equinox, or the equinoxes, or to the time of equal day and night;
as, the
equinoctial
line
.
2.
Pertaining to the regions or climate of the equinoctial line or equator; in or near that line;
as,
equinoctial
heat; an
equinoctial
sun.
3.
Pertaining to the time when the sun enters the equinoctial points;
as, an
equinoctial
gale or storm, that is, one happening at or near the time of the equinox, in any part of the world
.
Equinoctial colure
(Astron.)
,
the meridian passing through the equinoctial points.
Equinoctial line
(Astron.)
,
the celestial equator; – so called because when the sun is on it, the nights and days are of equal length in all parts of the world. See
Equator
.

Equinoctial points
(Astron.)
,
the two points where the celestial and ecliptic intersect each other; the one being in the first point of Aries, the other in the first point of Libra.
Equinoctial time
(Astron.)
reckoned in any year from the instant when the mean sun is at the mean vernal equinoctial point.

Eˊqui-noc′tial

,
Noun.
The equinoctial line.

Webster 1828 Edition


Equinoctial

EQUINOC'TIAL

,
Adj.
[L. oequus, equal, and nox, night.]
1.
Pertaining to the equinoxes; designating an equal length of day and night; as the equinoctial line.
2.
Pertaining to the regions or climate of the equinoctial line or equator; in or near that line; as equinoctial heat; an equinoctial sun; equinoctial wind.
3.
Pertaining to the time when the sun enters the equinoctial points; as an equinoctial gale or storm, which happens at or near the equinox, in any part of the world.
4.
Equinoctial flowers, flowers that open at a regular, stated hour.

EQUINOC'TIAL

,
Noun.
[for equinoctial line.]
In astronomy, a great circle of the sphere, under which the equator moves in its diurnal course. This should not be confounded with the equator, as there is a difference between them; the equator being movable, and the equinoctial immovable; the equator being drawn about the convex surface of the sphere, and the equinoctial on the concave surface of the magnus orbis. These words however are often confounded. When the sun, in its course through the ecliptic, comes to this circle, it makes equal days and nights in all parts of the globe. The equinoctial then is the circle which the sun describes, or appears to describe, at the time the days and nights are of equal length, viz. about the 21st of March and 23d of September.
Equinoctial points, are the two points wherein the equator and ecliptic intersect each other; the one, being in the first point of Aries, is called the vernal point or equinox; the other, in the first point of Libra, the autumnal point or equinox.
Equinoctial dial, is that whose plane lies parallel to the equinoctial.

Definition 2024


equinoctial

equinoctial

English

Alternative forms

Adjective

equinoctial (not comparable)

  1. (astronomy) Of or relating to the spring or autumnal equinox.
    an equinoctial gale or storm, i.e. one happening at or near the time of the equinox, in any part of the world
  2. (astronomy) Of or relating to the celestial equator.
  3. (uncommon) Equatorial: Of or relating to the equator of the Earth.

Synonyms

Translations

Derived terms

Noun

equinoctial (plural equinoctials)

  1. The great circle midway between the celestial poles; the celestial equator.
    • 1621, Robert Burton, The Anatomy of Melancholy, III.2.1.ii:
      The scorching beams under the equinoctial, or extremity of cold within the circle Arctic, […] cannot avoid or expel this heat, fury, and rage of mortal men.
  2. (rare) The terrestrial equator.

Translations

References