sharpness vs ill nature

sharpness and ill nature both are nouns.

Word	Noun	Adjective	Verb	Adverb
sharpness	Yes	No	No	No
ill nature	Yes	No	No	No

As nouns, ill nature is a hypernym of sharpness; that is, ill nature is a word with a broader meaning than sharpness:

sharpness (noun)	ill nature (noun)
harshness of manner	a disagreeable, irritable, or malevolent disposition
thinness of edge or fineness of point
a strong odor or taste property
the quality of being sharp and clear
the attribute of urgency in tone of voice
the quality of being keenly and painfully felt
a quick and penetrating intelligence