Antonyms of adj mighty

1 sense of mighty

Sense 1
mighty -- (having or showing great strength or force or intensity; "struck a mighty blow"; "the mighty logger Paul Bunyan"; "the pen is mightier than the sword"- Bulwer-Lytton)

INDIRECT (VIA powerful) -> powerless -- (lacking power)

Similarity of adj mighty

1 sense of mighty

Sense 1
mighty -- (having or showing great strength or force or intensity; "struck a mighty blow"; "the mighty logger Paul Bunyan"; "the pen is mightier than the sword"- Bulwer-Lytton)
       => powerful (vs. powerless) -- (having great power or force or potency or effect; "the most powerful government in western Europe"; "his powerful arms"; "a powerful bomb"; "the horse's powerful kick"; "powerful drugs"; "a powerful argument")

Synonyms of adv mighty

1 sense of mighty

Sense 1
mighty, mightily, powerful, right -- ((Southern regional intensive) very; to a great degree; "the baby is mighty cute"; "he's mighty tired"; "it is powerful humid"; "that boy is powerful big now"; "they have a right nice place"; "they rejoiced mightily")