what is bestie

Bestie is an informal term that refers to a persons best friend. It is commonly used to describe someone who knows you better than anyone else and with whom you share a close bond. The term has been used for decades by people describing their closest confidants, but it began appearing in dictionaries as a slang term some time after 2010. The word bestie is often used interchangeably with "BFF" to describe the one person you can trust completely to keep your secrets and be there for you no matter what.