As a Noun:
1. A law, decree or public statement that says you cannot do something. English = ban, prohibition.
As a Verb or Adjective:
1. To say publicly by decree or to make a law that says you cannot do something; to be officially not allowed. English = ban, prohibit; (be) banned, (be) prohibited, (be) illegal.
2. To order someone not to do something; to be not allowed. English = forbid; (be) forbidden.
1. Used alone to tell someone very forcefully to stop doing something, especially when you are in a position of authority and representing some organisation which rules against that activity. English = 'Stop! It's forbidden to do that.'