jus A right, deriving from a rule of law - a concept of Roman law. 1. jus naturale: what nature has taught all living things (an ideal to which the law should seek to conform). 2. Jus gentium: the law of peoples, i.e., law of universal application. 3. Jus civile: the law each people has settled for itself. Used also to refer to the entire corpus of Roman Law.