greet vs hail

greet is not a noun while hail is a noun.

Word	Noun	Adjective	Verb	Adverb
greet	No	No	Yes	No
hail	Yes	No	Yes	No

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

Other hyponyms of greet include shake hands, bob, curtsy, salute, present, salute, salute, herald, receive, welcome, say farewell, bid, wish.

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

greet (verb)	hail (verb)
react to in a certain way	greet enthusiastically or joyfully
express greetings upon meeting someone	call for
send greetings to	praise vociferously
be perceived by	be a native of
	precipitate as small ice particles