abruptness vs discourtesy

abruptness and discourtesy both are nouns.

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

As nouns, discourtesy is a hypernym of abruptness; that is, discourtesy is a word with a broader meaning than abruptness:

Other hypernyms of abruptness include rudeness.

abruptness (noun)	discourtesy (noun)
the quality of happening with headlong haste or without warning	a lack of politeness; a failure to show regard for others; wounding the feelings of others
the property possessed by a slope that is very steep	a manner that is rude and insulting
an abrupt discourteous manner	an expression of lack of respect