As a Noun:
1. Two people, especially school children, who are each others best friends. English = buddies, chums.
As a Verb or Adjective:
1. To be best friends with someone, especially while at school, if not ever since school. English = (be) buddies, (be) best friends, (be) mates.
Interactive:
1. Used alone to mean that you and your addressee have done something exactly alike (like order something in a restaurant) or think alike in some way. English = 'Hey, we're the same!', 'Great minds think alike!', and so on.
2. Used alone to mean that you and your addressee are, or are to be considered, very close and friendly; or should help each other (say in a game). English = 'Let's stick together!', 'Let's be buddies!', 'We're in this together!' and so on.