achromatic vs ebony

achromatic is not a noun while ebony is a noun.

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

achromatic (noun)	ebony (noun)
	a very dark black
	tropical tree of southern Asia having hard dark-colored heartwood used in cabinetwork
	hard dark-colored heartwood of the ebony tree; used in cabinetwork and for piano keys

achromatic (adjective)	ebony (adjective)
having no hue	of a very dark black