Antonyms of noun usefulness

1 sense of usefulness

Sense 1
utility, usefulness -- (the quality of being of practical use)
       Antonym of uselessness (Sense 1)
      => inutility, uselessness, unusefulness -- (the quality of having no practical use)

Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun usefulness

1 sense of usefulness

Sense 1
utility, usefulness -- (the quality of being of practical use)
       => quality -- (an essential and distinguishing attribute of something or someone; "the quality of mercy is not strained"--Shakespeare)