plain-clothes man

n．便衣警察，便衣刑警

placebo, placement, placenta, placental, placid, placidity, placidly, placket, plagiarism, plagiarist, plagiarize, plagiarize, plagiarise, plague, plague-ridden (also `plague-stricken), plaice, plaid, plain, plain clothes (esp of police officers), plain dealing, plain flour, plain-spoken, plainchant, plainly, plainness, plains, plainsman, plaint, plaintiff, plaintive, plaintively, plaintiveness, plait, plan, plane, plane geometry, plane sailing, plane-table, planet, planetarium, planetary,