precipitous vs precipitousness

precipitous is not a noun while precipitousness is a noun.

Word	Noun	Adjective	Verb	Adverb
precipitous	No	Yes	No	No
precipitousness	Yes	No	No	No

precipitous (noun)	precipitousness (noun)
	the property possessed by a slope that is very steep
	the quality of happening with headlong haste or without warning

precipitous (adjective)	precipitousness (adjective)
done with very great haste and without due deliberation
dangerously steep