adjective
useless
Synonyms: abortive, anticlimactic, barren, bootless, defeasible, emasculate, feckless, feeble, forceless, fruitless, futile, idle, impotent, inadequate, incompetent, indecisive, ineffectual, inefficacious, inefficient, inept, inferior, innocuous, inoperative, lame, limited, neutralized, no go, no way, not effective, nugatory, null, paltry, powerless, slack-spined, spineless, unable, unavailable, unavailing, unfruitful, unproductive, unprofitable, unsuccessful, vain, void, withered, worthless
Antonyms: effective
adjective
weak, useless
Synonyms: abortive, anticlimactic, barren, bootless, defeasible, feckless, feeble, forceless, fruitless, futile, idle, impotent, inadequate, incompetent, indecisive, inefficacious, inefficient, inept, inferior, innocuous, inoperative, invertebrate, lame, limited, neutralized, nugatory, null, null and void, paltry, powerless, spineless, unable, unavailing, unfruitful, unproductive, unprofitable, unsuccessful, vain, void, withered, worthless
Antonyms: competent, effective, effectual, efficient, powerful, strong, useful