abruptness vs curtness

abruptness and curtness both are nouns.

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

As nouns, abruptness and curtness are synonyms defined as:

Other synonyms of abruptness include brusqueness, gruffness, shortness.

abruptness (noun)	curtness (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