zenith vs sphere

zenith and sphere both are nouns.

Word	Noun	Adjective	Verb	Adverb
zenith	Yes	No	No	No
sphere	Yes	No	No	No

zenith (noun)	sphere (noun)
the point above the observer that is directly opposite the nadir on the imaginary sphere against which celestial bodies appear to be projected	any spherically shaped artifact
	a particular aspect of life or activity
	the geographical area in which one nation is very influential
	the apparent surface of the imaginary sphere on which celestial bodies appear to be projected
	a solid figure bounded by a spherical surface (including the space it encloses)
	a three-dimensional closed surface such that every point on the surface is equidistant from the center
	a particular environment or walk of life