new broom (1)youdaoicibaDictYouDict[new broom 词源字典]
"A person who or thing which effects fundamental or numerous alterations; especially a newly appointed person who vigorously sets about making changes in personnel, procedures, etc", Late 18th cent.; earliest use found in Frederick Reynolds (1764–1841), playwright. From new + broom, with allusion to the proverb new brooms sweep clean.[new broom etymology, new broom origin, 英语词源]