\E`qui*noc"tial\, a. [L. aequinoctials, fr.
aequinoctium equinox: cf. F. ['e]quinoxial. 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}.
         Thrice the equinoctial line He circled. --Milton.
{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.

\E`qui*noc"tial\, n.
The equinoctial line.