equinoctial line vs equinoctial

equinoctial line and equinoctial both are nouns.

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

As nouns, equinoctial line and equinoctial are synonyms defined as:

equinoctial line and equinoctial: the great circle on the celestial sphere midway between the celestial poles

Other synonyms of equinoctial line include celestial equator, equinoctial circle.

equinoctial line (noun)	equinoctial (noun)
the great circle on the celestial sphere midway between the celestial poles	the great circle on the celestial sphere midway between the celestial poles

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