The antonyms for the word "crossbreeds" are purebred, pedigreed, or thoroughbred. A purebred animal is one that comes from a long line of ancestors of the same breed, and has a known and predictable lineage. A pedigreed animal is similar to a purebred animal, but it may have a few unknown or unconfirmed ancestors. A thoroughbred animal is one that has been bred for generations for a specific purpose, such as racing or hunting. These antonyms describe animals that are bred for a specific purpose, with a known and predictable lineage. In contrast, crossbreeds are animals that are a mix of two or more breeds, and their lineage may be less predictable.