"Buddy" is a name that you can call someone instead of their real name. The word "buddy" means "friend".

English speakers mostly use "buddy" when talking to a younger man. Here are some specific relationships in which someone might call someone else "buddy":

• Fathers, uncles, grandfathers, etc. often call their sons, nephews, and grandsons "buddy" from young childhood until their teenage years, and sometimes longer.
• Male friends who are similar ages sometimes call each other "buddy".

When you call a stranger "buddy", it's just a little bit rude and aggressive. For example, if a man is taking a long time to get a ticket at an automatic ticket machine in front of you, you might say this if you get really frustrated:

Hey buddy, can you speed it up?