ill nature vs sharpness

ill nature and sharpness both are nouns.

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

As nouns, sharpness is a hyponym of ill nature; that is, sharpness is a word with a more specific, narrower meaning than ill nature:

ill nature (noun)	sharpness (noun)
a disagreeable, irritable, or malevolent disposition	harshness of manner
	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