As a Noun:
1. A feeling you have when you wish you had not done something. English = regret.
As a Verb or Adjective:
1. To wish you had not done something, especially something which has caused someone pain or difficulties. English = regret, feel sorry.
Interactive:
1. Used alone as a way of apologising to someone for something that you have done which has upset them or caused them difficulties. English = 'Sorry', 'I'm sorry' and so on.