The Oxford Thesaurus An A-Z Dictionary of Synonyms - useless adj.

1) ineffective, ineffectual, unserviceable, impractical, impracticable, unpractical, unavailing, vain, pointless, purposeless, idle, futile, unproductive, unsuccessful, impotent, effete, sterile, barren, abortive, unusable, bootless, worthless, Rare inutile: The treatment that she tried was quite useless. 2) inefficient, incompetent, unproductive, ineffectual, ineffective, hopeless, inept: My dachshund has proved totally useless as a watchdog.