suddenness vs precipitancy

suddenness and precipitancy both are nouns.

Word	Noun	Adjective	Verb	Adverb
suddenness	Yes	No	No	No
precipitancy	Yes	No	No	No

As nouns, suddenness and precipitancy are synonyms defined as:

suddenness and precipitancy: the quality of happening with headlong haste or without warning

Other synonyms of suddenness include abruptness, precipitance, precipitateness, precipitousness.

suddenness (noun)	precipitancy (noun)
the quality of happening with headlong haste or without warning	the quality of happening with headlong haste or without warning