jaw-breaker (n.)youdaoicibaDictYouDict[jaw-breaker 词源字典]
also jawbreaker 1839, "word hard to pronounce" (jawbreakingly, in reference to pronouncing words, is from 1824), from jaw (n.) + agent noun from break (v.). As a type of candy, by 1911.[jaw-breaker etymology, jaw-breaker origin, 英语词源]