a policeman who wears ordinary clothes when working, rather than a uniform
plainclothesman in American English
(ˈpleinˈklouzmən, -ˌmæn, -ˈklouðz-)
nounWord forms: plural-men (-mən, -ˌmen)
a police officer, esp. a detective, who wears ordinary civilian clothes while on duty
Also: plainclothes man
Word origin
[1925–30; plainclothes + man1]This word is first recorded in the period 1925–30. Other words that entered Englishat around the same time include: Nazi, distinctive feature, hot spot, recycle, runout
Examples of 'plainclothesman' in a sentence
plainclothesman
All the time he poured Stein's coffee, he was grousing under his breath to a plainclothesman just on the other side of the order window.