Incommutable \In`com*mut"a*ble\, a. [L. incommutabilis: cf. F. incommutable. See {In-} not, and {Commutable}.] Not commutable; not capable of being exchanged with, or substituted for, another. --Cudworth. -- {In`com*mut"a*ble*ness}, n. -- {In`com*mut"a*bly}, adv.