a. 1. Righteous; upright; just; good; -- said of persons. [ Obs. ] Chaucer. [ 1913 Webster ]
2. Consonant to justice; just; as, a rightful cause. [ 1913 Webster ]
3. 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. [ 1913 Webster ]
4. Belonging, held, or possessed by right, or by just claim; as, a rightful inheritance; rightful authority. [ 1913 Webster ]