forbidding in WordNet English dictionary

1. threatening or foreshadowing evil or tragic developments
   "a baleful look"; "forbidding thunderclouds"; "his tone became menacing"; "ominous rumblings of discontent"; "sinister storm clouds"; "a sinister smile"; "his threatening behavior"; "ugly black clouds"; "the situation became ugly"
   baleful  forbidding  menacing  minacious  minatory  ominous  sinister  threatening 
   
2. harshly uninviting or formidable in manner or appearance
   "a dour, self-sacrificing life"; "a forbidding scowl"; "a grim man loving duty more than humanity"; "undoubtedly the grimmest part of him was his iron claw"- J.M.Barrie
   dour  forbidding  grim 
   

1. an official prohibition or edict against something
   ban  banning  forbiddance  forbidding