zenith vs celestial point

zenith and celestial point both are nouns.

Word	Noun	Adjective	Verb	Adverb
zenith	Yes	No	No	No
celestial point	Yes	No	No	No

As nouns, celestial point is a hypernym of zenith; that is, celestial point is a word with a broader meaning than zenith:

zenith: the point above the observer that is directly opposite the nadir on the imaginary sphere against which celestial bodies appear to be projected
celestial point: a point in the heavens (on the celestial sphere)

zenith (noun)	celestial point (noun)
the point above the observer that is directly opposite the nadir on the imaginary sphere against which celestial bodies appear to be projected	a point in the heavens (on the celestial sphere)