cop

n.警察

cool-headed, coolant, cooler, coolie, cooling, cooling tower, cooling-off, coolly, coolness, coon, coop, cooper, cooperate, cooperation, cooperative, coordinate, coordination, coordinator, coorperation, coot, cop-out, copain, copartner, copartnership, cope, cope with, copeck (also kopeck), Copernican, copier, coping, coping-stone, copious, copiously, copper, copper beech, copper-bottomed, copperhead, copperplate, coppice, copra,