The word "chain store", which refers to a retail store that is part of a group of stores under the same brand, can have many antonyms depending on the context. One antonym could be "independent store", which refers to a retail store that is not affiliated with any particular brand or chain. Another antonym could be "mom-and-pop store", which refers to a small, family-owned store that typically specializes in specific products or services. Other antonyms for "chain store" might include "boutique", "specialty store", "department store", "thrift store", or "discount store". Each of these words represents a different type of retail operation that is distinct from the traditional chain store model.