justice vs rightfulness

justice and rightfulness both are nouns.

Word	Noun	Adjective	Verb	Adverb
justice	Yes	No	No	No
rightfulness	Yes	No	No	No

As nouns, rightfulness is a hyponym of justice; that is, rightfulness is a word with a more specific, narrower meaning than justice:

Other hyponyms of justice include equity, fairness, right.

justice (noun)	rightfulness (noun)
judgment involved in the determination of rights and the assignment of rewards and punishments	anything in accord with principles of justice
the quality of being just or fair
a public official authorized to decide questions brought before a court of justice