achromatic vs argent

achromatic is not a noun while argent is a noun.

Word	Noun	Adjective	Verb	Adverb
achromatic	No	Yes	No	No
argent	Yes	Yes	No	No

achromatic (noun)	argent (noun)
	a metal tincture used in heraldry to give a silvery appearance

achromatic (adjective)	argent (adjective)
having no hue	of lustrous grey; covered with or tinged with the color of silver