nedopustivo

1. impermissibly; unacceptably
   Nedopustivo je da pacijenti čekaju po šest sati. — It is unacceptable for patients to wait six hours.
   Ponašao se nedopustivo grubo prema koleginici. — He behaved unacceptably rudely toward his colleague.

Often used in the construction nedopustivo je da + verb.