Antonyms of noun ineffectiveness

1 sense of ineffectiveness

Sense 1
ineffectiveness, ineffectualness, ineffectuality -- (lacking the power to be effective)
       Antonym of effectiveness (Sense 1)
      => effectiveness, effectivity, effectualness, effectuality -- (power to be effective; the quality of being able to bring about an effect)

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

1 sense of ineffectiveness

Sense 1
ineffectiveness, ineffectualness, ineffectuality -- (lacking the power to be effective)
       => powerlessness, impotence, impotency -- (the quality of lacking strength or power; being weak and feeble)