inefficaciousadjective · Level 3 SAT1lacking the power to produce a desired effectThe remedy was found to be inefficacious in clinical trials involving more than two thousand patients.ModuleLevel 3RegisteracademicCollectionCollection 050SAT Complete planAlso in Collection 050unregenerate, inalienable, unmanageable, unsubduable, beatific, fictile, impenitent, unforgiving and 1 more