sulkiness vs mood

sulkiness and mood both are nouns.

Word	Noun	Adjective	Verb	Adverb
sulkiness	Yes	No	No	No
mood	Yes	No	No	No

As nouns, mood is a hypernym of sulkiness; that is, mood is a word with a broader meaning than sulkiness:

Other hypernyms of sulkiness include humor, humour, temper.

sulkiness (noun)	mood (noun)
a sullen moody resentful disposition	a characteristic (habitual or relatively temporary) state of feeling
a feeling of sulky resentment	verb inflections that express how the action or state is conceived by the speaker
a mood or display of sullen aloofness or withdrawal	the prevailing psychological state