precipitousness vs precipitous

precipitousness is a noun but precipitous is not a noun.

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

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

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