Found 2 items, similar to inefficacious.
English → English (WordNet) Definition: inefficacious inefficacious adj : lacking the power to produce a desired effect; “laws that are inefficacious in stopping crime” [ant: efficacious]
English → English (gcide) Definition: Inefficacious Inefficacious \In*ef`fi*ca"cious\, a. [Pref. in- not + efficacious: cf. F. inefficace, L. inefficax.] Not efficacious; not having power to produce the effect desired; inadequate; incompetent; inefficient; impotent. --Boyle. [1913 Webster] The authority of Parliament must become inefficacious . . . to restrain the growth of disorders. --Burke. [1913 Webster] Note: Ineffectual, says Johnson, rather denotes an actual failure, and inefficacious an habitual impotence to any effect. But the distinction is not always observed, nor can it be; for we can not always know whether means are inefficacious till experiment has proved them ineffectual. Inefficacious is therefore sometimes synonymous with ineffectual. [1913 Webster]