Rugby Union is a popular sport that originated in England during the 19th century. It is a full-contact team sport that involves two teams of 15 players each. While this sport is commonly known as Rugby Union, there are various synonyms that can be used to describe it. Some of the synonyms for Rugby Union include Rugby, Fifteens, Union, Union Football, and Rugby Football. These terms are often used interchangeably and all refer to the same sport. The history and popularity of Rugby Union have led to the creation of many colloquial names as well, such as footy, rugger, and simply, rugby.