The term "mixed dog breed" is a misnomer when referring to dogs that are a literal mix of breeds. The terms crossbred, hybrid or designer dogs are used to define dogs that are intentionally bred from two or more separate recognized dog breeds.
The term mixed breed is a preferred synonym for the word "mongrel" in the United States. Some people jokingly refer to them as a "Heinz 57"or Heinz Hound dog. This term is a play on words in reference to the H.J. Heinz company's steak sauce product that is supposed to contain 57 ingredients.
Dogs that are not purebred are referred to as mongrels in the United Kingdom. In the United States and Canada, they are often affectionately referred to as "mutts." In Hawaii, mixed dogs are called "poi dogs." Some American dog clubs and registries use the term "All American" when referring to these dogs.