steep vs steepness

steep and steepness both are nouns.

Word	Noun	Adjective	Verb	Adverb
steep	Yes	Yes	Yes	No
steepness	Yes	No	No	No

steep (noun)	steepness (noun)
a steep place (as on a hill)	the property possessed by a slope that is very steep

steep (adjective)	steepness (adjective)
having a sharp inclination
of a slope; set at a high angle
greatly exceeding bounds of reason or moderation

steep (verb)	steepness (verb)
let sit in a liquid to extract a flavor or to cleanse
devote (oneself) fully to