equinoctial vs equinox

equinoctial and equinox both are nouns.

Word	Noun	Adjective	Verb	Adverb
equinoctial	Yes	Yes	No	No
equinox	Yes	No	No	No

equinoctial (noun)	equinox (noun)
the great circle on the celestial sphere midway between the celestial poles	(astronomy) either of the two celestial points at which the celestial equator intersects the ecliptic
	either of two times of the year when the sun crosses the plane of the earth's equator and day and night are of equal length

equinoctial (adjective)	equinox (adjective)
relating to an equinox (when the lengths of night and day are equal)
relating to the vicinity of the equator