nitrous acid vs nitrify

nitrous acid is a noun but nitrify is not a noun.

Word	Noun	Adjective	Verb	Adverb
nitrous acid	Yes	No	No	No
nitrify	No	No	Yes	No

nitrous acid (noun)	nitrify (noun)
an unstable inorganic acid known only in solution and as nitrite salts

nitrous acid (verb)	nitrify (verb)
	treat (soil) with nitrates
	treat with nitrogen or a nitrogen compound
	convert into nitric acid, nitrous acid, or nitrate, especially with the action of nitrobacteria