abruptness vs brusqueness

abruptness and brusqueness both are nouns.

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

As nouns, abruptness and brusqueness are synonyms defined as:

Other synonyms of abruptness include curtness, gruffness, shortness.

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