buddy

noun
  1. A close friend or companion; someone with whom one shares a strong bond or camaraderie. noun
    I've known him since childhood, he's my best buddy.
    She went to the movies with her buddy from work.
  2. A term of friendly address used to refer to someone, often in a casual or informal manner. noun
    Hey buddy, how's it going?
    Listen, buddy, I think you dropped this.
  3. To become friends or to form a close relationship with someone. verb
    They buddied up during the school trip.
    He quickly buddied with his new teammates.