pour vs rain

pour is not a noun while rain is a noun.

Word	Noun	Adjective	Verb	Adverb
pour	No	No	Yes	No
rain	Yes	No	Yes	No

As verbs, rain is a hypernym of pour; that is, rain is a word with a broader meaning than pour:

Other hypernyms of pour include rain down.

pour (noun)	rain (noun)
	anything happening rapidly or in quick successive
	water falling in drops from vapor condensed in the atmosphere
	drops of fresh water that fall as precipitation from clouds

pour (verb)	rain (verb)
move in large numbers	precipitate as rain
flow in a spurt
cause to run
pour out gradually, so as to separate out sediment
supply in large amounts or quantities
rain heavily