plain clothes

or plain·clothes

plural noun

clothing other than one's uniform, especially civilian clothes worn on duty by a police officer.

Origin of plain clothes

First recorded in 1815–25

Related formsplain-clothes, plain·clothes, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for plain clothes

Contemporary Examples of plain clothes

Outside at the taxi stand, the men approached and finally identified themselves: They turned out to be plain-clothes police.
How a Blogger Blocked Sex Slavery
Abigail Pesta
March 22, 2011

Historical Examples of plain clothes

“There are half a dozen plain-clothes men in the audience,” he said.
The Crimson Tide
Robert W. Chambers
The other two I guessed as plain-clothes men from Vancouver.
The Spoilers of the Valley
Robert Watson
"Well, yes, sir," admitted the plain-clothes man with reluctance.
Steve and the Steam Engine
Sara Ware Bassett
"It's all right, Sam," said the plain-clothes policeman with a grin.
The Daffodil Mystery
Edgar Wallace
It was signed by the chief of the Baltimore plain-clothes force.
The Winning Clue
James Hay, Jr.

British Dictionary definitions for plain clothes

plain clothes

pl n

1. ordinary clothes, as distinguished from uniform, as worn by a police detective on duty
2. (as modifier)a plain-clothes policeman

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for plain clothes

"ordinary dress" (as opposed to military uniform), 1822; of police detectives, it is attested from 1842. Also plainclothes.