"not capable," 1590s, from French incapable (16c.) and directly from Medieval Latin incapabilis "incapable," from in- "not" (see in- (1)) + capabilis "receptive; able to grasp or hold" (see capable). Related: Incapably; incapability.
incapable of solution
incapable of carrying a tune
he is incapable of understanding the matter
incapable of doing the work
simply incapable of lying