noun, plural plain·clothes·men [pleyn–klohz-muh n, -men, –klohth z-] /ˈpleɪnˈkloʊz mən, -ˌmɛn, -ˈkloʊðz-/.
- a police officer, especially a detective, who wears ordinary civilian clothes while on duty.
noun, plural plain·clothes·men [pleyn–klohz-muh n, -men, –klohth z-] /ˈpleɪnˈkloʊz mən, -ˌmɛn, -ˈkloʊðz-/.