steepness vs abruptness

steepness and abruptness both are nouns.

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

As nouns, steepness and abruptness are synonyms defined as:

steepness and abruptness: the property possessed by a slope that is very steep

Other synonyms of steepness include precipitousness.

steepness (noun)	abruptness (noun)
the property possessed by a slope that is very steep	the quality of happening with headlong haste or without warning
	the property possessed by a slope that is very steep
	an abrupt discourteous manner