Definition of new-broom in US English:

new-broom

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.

Pronunciation

new-broom

/ˌnjuːˈbruːm/