(usually of a police officer) Wearing ordinary civilian clothes instead of a uniform, in order to avoid detection.

Ordinary civilian clothes, rather than uniform.

plainclothes; wearing ordinary clothes instead of a uniform in order to avoid detection.

plural of plainclothes man

Alternative spelling of plainclothesman

A police officer (especially a detective) who wears civilian clothes when on duty.

plural of plainclothesman

A female police officer (especially a detective) who wears civilian clothes when on duty.

plural of plainclotheswoman

(rare) A police officer (especially a detective) of any gender who wears civilian clothes when on duty.