come down vs hail

come down is not a noun while hail is a noun.

Word	Noun	Adjective	Verb	Adverb
come down	No	No	Yes	No
hail	Yes	No	Yes	No

As verbs, hail is a hyponym of come down; that is, hail is a word with a more specific, narrower meaning than come down:

Other hyponyms of come down include rain, rain down, spat, snow, sleet.

come down (noun)	hail (noun)
	enthusiastic greeting
	many objects thrown forcefully through the air
	precipitation of ice pellets when there are strong rising air currents

come down (verb)	hail (verb)
get sick	greet enthusiastically or joyfully
be the essential element	call for
criticize or reprimand harshly	praise vociferously
move downward and lower, but not necessarily all the way	be a native of
fall from clouds	precipitate as small ice particles