- inefficacious
- adj1. ineffective, ineffectual, incapable, inadequate, inefficient, incompetent, inept; useless, inutile, worthless, valueless, meritless, nugatory.2. futile, vain, bootless, unavailing, idle; unproductive, unyielding, barren, abortive, sterile, infertile; unprofitable, profitless, unremunerative, unrewarding, unpaying, gainless; unsuccessful, Inf. no-go, to no avail, to no purpose, for naught.3. weak, feeble, powerless, lame, effete, impotent.
A Note on the Style of the synonym finder. 2014.