ill humour vs crossness

ill humour and crossness both are nouns.

Word	Noun	Adjective	Verb	Adverb
ill humour	Yes	No	No	No
crossness	Yes	No	No	No

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

Other hyponyms of ill humour include moodiness, choler, fretfulness, fussiness, irritability, peevishness, petulance.

ill humour (noun)	crossness (noun)
an angry and disagreeable mood	a disposition to be ill-tempered
	an irritable petulant feeling