As a Noun:
1. A feeling of wishing that you had not done something. English = regret.
As a Verb or Adjective:
1. To wish that you had not done something. English = (be) sorry, regret.
Interactive:
1. Used alone to express the feeling you have when you wish that you had not done something. English = 'I'm sorry', 'How could I have done that?'