Courteousness is a related term of gentility.
As nouns the difference between courteousness and gentility
is that courteousness is the characteristic of being courteous while gentility is (uncountable) the state of being elegant, genteel, having good breeding, or being socially superior.
courteousness
English
Noun
(-)
The characteristic of being courteous.
gentility
English
Noun
(uncountable) The state of being elegant, genteel, having good breeding, or being socially superior.
The upper classes, the gentry.