Buddy-buddy is an informal term used to describe close friends or companionship. However, there are several other synonyms that convey the same sense of camaraderie and familiarity. Some of these are - chummy, intimate, familiar, friendly, congenial, amiable, affable, and companionable. These words are all perfect synonyms for buddy-buddy and can be used in different contexts and settings to express the same meaning. By choosing these synonyms, one can add more variety and interest to their writing or conversation. In essence, they all refer to a strong bond of friendship that brings people together, and all suggest a high level of comfort and ease between individuals.