new broom1
/ˌnjuː ˈbruːm/noun
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.
- In early use sometimes simply: a person who has been recently appointed or who has only recently arrived..
Origin
Late 18th century; earliest use found in Frederick Reynolds (1764–1841), playwright. From new + broom, with allusion to the proverb new brooms sweep clean.
new-broom2
/ˌnjuːˈbruːm/verb
[no object] To set about making widespread or fundamental changes. Also with object: to make (one's way) like a new broom.
Origin
1950s; earliest use found in Ngaio Marsh (1895–1982), detective novelist and theatre director. From new broom.