precipitous vs precipitant

precipitous is not a noun while precipitant is a noun.

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

As adjectives, precipitous and precipitant are synonyms defined as:

precipitous and precipitant: done with very great haste and without due deliberation

Other synonyms of precipitous include hasty, overhasty, precipitate.

precipitous (noun)	precipitant (noun)
	an agent that causes a precipitate to form

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