plain clothes

US /ˌpleɪn ˈkloʊðz/
UK /ˌpleɪn ˈkloʊðz/
"plain clothes" picture
1.

burgerkleding, gewone kleding

ordinary clothes, not a uniform or special costume

:
The detective was working in plain clothes.
De detective werkte in burgerkleding.
Security personnel often blend in plain clothes at events.
Beveiligingspersoneel mengt zich vaak in burgerkleding op evenementen.