1. A very close friend. Someone who you have to fix common misspelled words during online conversations with. Someone you go to the gym with, only not to work out, but to chill instead. Someone who you have to help manage their money with because they can't control it themselves.
2. A person who calls you a faggot and you call a queer in return.
1. Person 1: Hey! Let's be friends! we have a lot in common!
Person 1: We can be FB/GB/LB/and whatever buddies there is out there!
Person 2: How about we cut it short to BB for Best Buddy.
Person 1: Good idea!