Gobstoppers, known as jawbreakers in Canada and the United States, are a type of hard candy. They are usually round, usually range from about 1 cm across to 3 cm across (though much bigger gobstoppers can sometimes be found in Canadian/US candy stores, some stores or stands in Europe and many theme parks, up to 8 cm in diameter) and are traditionally very hard.The term gobstopper derives from 'gob', which is slang in United Kingdom and Ireland for mouth.