hoar vs old

hoar and old both are nouns.

Word	Noun	Adjective	Verb	Adverb
hoar	Yes	Yes	No	No
old	Yes	Yes	No	No

hoar (noun)	old (noun)
ice crystals forming a white deposit (especially on objects outside)	past times

hoar (adjective)	old (adjective)
showing characteristics of age, especially having grey or white hair	of long duration; not new
	(used especially of persons) having lived for a relatively long time or attained a specific age
	skilled through long experience
	(used for emphasis) very familiar
	excellent
	just preceding something else in time or order
	belonging to some prior time