ill-humored vs gruff

ill-humored and gruff both are adjectives.

Word	Noun	Adjective	Verb	Adverb
ill-humored	No	Yes	No	No
gruff	No	Yes	No	No

As adjectives, ill-humored and gruff are synonyms defined as:

Other synonyms of ill-humored include crusty, curmudgeonly, ill-humoured.

ill-humored (adjective)	gruff (adjective)
brusque and surly and forbidding	deep and harsh sounding as if from shouting or illness or emotion
	brusque and surly and forbidding