The term 'CHANG's Siamese Twin' refers to the conjoined twins CHANG and Eng Bunker, who were born in Siam (now Thailand) in 1811. The twins were joined at the sternum by a small piece of cartilage and shared a liver. They became famous for their unique condition and toured the world as a sideshow attraction. The term 'CHANG's Siamese Twin' is derived from their surname, and is often used to refer to conjoined twins in general. The crossword solution ENG is an abbreviation for the word 'ENGINEER, ' which was the profession of the twins' father.