The word "bestie" is a modern slang term used to describe a close friend. However, there are many synonyms for this word that can be used to add variety to your vocabulary. Some of the common synonyms for "bestie" are buddy, pal, chum, comrade, confidant, mate, and companion. Other synonyms for "bestie" include confederate, amigo, ally, associate, co-worker, cohort, and partner. These words can be used interchangeably to refer to close friends with whom you share a special bond. Experiment with different synonyms for "bestie" to add more color and personality to your communication with friends and acquaintances.