suddenness vs precipitance

suddenness and precipitance both are nouns.

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

As nouns, suddenness and precipitance are synonyms defined as:

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

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

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