altitude vs ceiling

altitude and ceiling both are nouns.

Word	Noun	Adjective	Verb	Adverb
altitude	Yes	No	No	No
ceiling	Yes	No	No	No

As nouns, ceiling is a hyponym of altitude; that is, ceiling is a word with a more specific, narrower meaning than altitude:

Other hyponyms of altitude include level.

altitude (noun)	ceiling (noun)
elevation especially above sea level or above the earth's surface	the overhead upper surface of a covered space
angular distance above the horizon (especially of a celestial object)	(meteorology) altitude of the lowest layer of clouds
the perpendicular distance from the base of a geometric figure to the opposite vertex (or side if parallel)	maximum altitude at which a plane can fly (under specified conditions)
	an upper limit on what is allowed