Oh dear cherry-picking again. This is the whole definition given at your reference - my bold.
the quality of being just; righteousness, equitableness, or moral rightness:to uphold the justice of a cause.
rightfulness or lawfulness, as of a claim or title; justness of ground or reason:to complain with justice.
the moral principle determining just conduct.
conformity to this principle, as manifested in conduct; just conduct, dealing, or treatment.
the administering of deserved punishment or reward.
the maintenance or administration of what is just by law, as by judicial or other proceedings:a court of justice.