abruptness vs precipitance

abruptness and precipitance both are nouns.

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

As nouns, abruptness and precipitance are synonyms defined as:

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

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

abruptness (noun)	precipitance (noun)
the quality of happening with headlong haste or without warning	the quality of happening with headlong haste or without warning
the property possessed by a slope that is very steep
an abrupt discourteous manner