1. immūtābĭlis (inm-), e, adj. [2. in-mutabilis], unchangeable, unalterable, immutable (rare but class.): esse causas immutabiles easque aeternas, Cic. Fat. 12, 28; so, immutabilis et aeterna res, id. Rep. 3, 2: nec magis immutabile ex vero in falsum, id. Fat. 9, 18: res (with stabilis), id. Univ. 3: comprehensio (with stabilis), id. Ac. 2, 8, 23: spatia, id. N. D. 2, 19, 49: eadem ratio, quae fuit futuraque, donec res eaedem manebunt, inmutabilis est, Liv. 22, 39, 10: necessitas, Quint. 2, 13, 1: pondus verborum (with grave), Stat. Th. 1, 212.
Comp.: concordi populo nihil esse immutabilius, nihil firmius, Cic. Rep. 1, 32.
Adv.: immūtābĭlĭter, unchangeably, Dig. 45, 1, 99, § 1; App. de Mundo, p. 74.