ceiling vs upper surface

ceiling and upper surface both are nouns.

Word	Noun	Adjective	Verb	Adverb
ceiling	Yes	No	No	No
upper surface	Yes	No	No	No

As nouns, upper surface is a hypernym of ceiling; that is, upper surface is a word with a broader meaning than ceiling:

ceiling (noun)	upper surface (noun)
the overhead upper surface of a covered space	the side that is uppermost
(meteorology) altitude of the lowest layer of clouds
maximum altitude at which a plane can fly (under specified conditions)
an upper limit on what is allowed