Answer: unheardof

AnswerCrossword Clue
UNHEARDOFOutrageous
UNHEARDOFWithout precedent
UNHEARDOFLike the first ever
UNHEARDOFNot even rare
UNHEARDOFSimply not done
UNHEARDOFRarer than rare
UNHEARDOFWithout precedent.
UNHEARDOFTotally new.
UNHEARDOFUnprecedented
UNHEARDOFShocking, as behavior