Antonyms of adv permissibly

1 sense of permissibly

Sense 1
permissibly, allowably -- (in a permissible manner)
       Antonym of impermissibly (Sense 1)
      => impermissibly -- (not permissibly; "the radon level in the basement was impermissibly high")

Synonyms of adv permissibly

1 sense of permissibly

Sense 1
permissibly, allowably -- (in a permissible manner)