clouding up vs vapor

clouding up and vapor both are nouns.

Word	Noun	Adjective	Verb	Adverb
clouding up	Yes	No	No	No
vapor	Yes	No	No	No

As nouns, vapor is a hypernym of clouding up; that is, vapor is a word with a broader meaning than clouding up:

Other hypernyms of clouding up include evaporation, vaporisation, vaporization, vapour.

clouding up (noun)	vapor (noun)
the process whereby water particles become visible in the sky	the process of becoming a vapor
	a visible suspension in the air of particles of some substance