(1):
(a.) Consonant to justice; just; as, a rightful cause.
(2):
(a.) Having the right or just claim according to established laws; being or holding by right; as, the rightful heir to a throne or an estate; a rightful king.
(3):
(a.) Belonging, held, or possessed by right, or by just claim; as, a rightful inheritance; rightful authority.
(4):
(a.) Righteous; upright; just; good; - said of persons.