celestial equator vs equinoctial circle

celestial equator and equinoctial circle both are nouns.

Word	Noun	Adjective	Verb	Adverb
celestial equator	Yes	No	No	No
equinoctial circle	Yes	No	No	No

As nouns, celestial equator and equinoctial circle are synonyms defined as:

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

Other synonyms of celestial equator include equinoctial, equinoctial line.

celestial equator (noun)	equinoctial circle (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