gruffness vs harshness

gruffness and harshness both are nouns.

Word	Noun	Adjective	Verb	Adverb
gruffness	Yes	No	No	No
harshness	Yes	No	No	No

As nouns, harshness is a hypernym of gruffness; that is, harshness is a word with a broader meaning than gruffness:

Other hypernyms of gruffness include roughness.

gruffness (noun)	harshness (noun)
a throaty harshness	the quality of being harsh or rough or grating to the senses
an abrupt discourteous manner	excessive sternness
	the roughness of a substance that causes abrasions
	the quality of being cruel and causing tension or annoyance