charcoal vs greyness

charcoal and greyness both are nouns.

Word	Noun	Adjective	Verb	Adverb
charcoal	Yes	Yes	Yes	No
greyness	Yes	No	No	No

As nouns, greyness is a hypernym of charcoal; that is, greyness is a word with a broader meaning than charcoal:

Other hypernyms of charcoal include gray, grayness, grey.

charcoal (noun)	greyness (noun)
a stick of black carbon material used for drawing	a neutral achromatic color midway between white and black
a drawing made with a stick of black carbon material
a very dark grey color
a carbonaceous material obtained by heating wood or other organic matter in the absence of air

charcoal (adjective)	greyness (adjective)
of a very dark grey

charcoal (verb)	greyness (verb)
draw, trace, or represent with charcoal