Antonyms of adv unjustifiably

1 sense of unjustifiably

Sense 1
unjustifiably, inexcusably -- (without any excuse; "he is unjustifiably harsh on her")
       Antonym of justifiably (Sense 1)
      => justifiably -- (with good reason; "he is justifiably bitter")

Synonyms of adv unjustifiably

1 sense of unjustifiably

Sense 1
unjustifiably, inexcusably -- (without any excuse; "he is unjustifiably harsh on her")