brattiness vs jejuneness

brattiness and jejuneness both are nouns.

Word	Noun	Adjective	Verb	Adverb
brattiness	Yes	No	No	No
jejuneness	Yes	No	No	No

As nouns, jejuneness is a hypernym of brattiness; that is, jejuneness is a word with a broader meaning than brattiness:

brattiness: The state or condition of acting like a brat, being unruly and impolite.
jejuneness: lacking and evidencing lack of experience of life

Other hypernyms of brattiness include callowness, juvenility.

brattiness (noun)	jejuneness (noun)
The state or condition of acting like a brat, being unruly and impolite.	the quality of being vapid and unsophisticated
	quality of inadequate nutritive value
	lacking and evidencing lack of experience of life