uselessness

Synonyms
1. fruitless, profitless, valueless, worthless, inutile. Useless, futile, ineffectual, vain refer to that which is unavailing. That is useless which is unavailing because of the circumstances of the case or some inherent defect: It is useless to cry over spilt milk. Futile suggests wasted effort and complete failure to attain a desired end: All attempts were futile. That which is ineffectual weakly applies energy in an ill-advised way and does not produce a desired effect: an ineffectual effort. That which is vain is fruitless or hopeless even after all possible effort: It is vain to keep on hoping. 2. unserviceable, unusable.

Antonyms
1. effective.