名词 countersink:

1. a hole (usually in wood) with the top part enlarged so that a screw or bolt will fit into it and lie below the surface

2. a bit for enlarging the upper part of a hole

动词 countersink:

1. insert (a nail or screw below the surface, as into a countersink)

counterego反向自我countern.柜台；筹码；计数器；反驳adj.相反的adv.与…相反地v.反对；反击counter-currention exchange逆流交换counter--particle tracing反向粒子示踪Countermeasures Dispenser Pod对抗发散隔离舱counterforce on the pile head桩顶反力Counter Top Gas Noodle Cooker台式燃气煮面炉countersunk ovel-head rivet埋头圆项铆钉counterbalance overhead sling抗平衡吊带countermeasures of cataloging编目对策countermeasures of government政府行为counter-clockwise direction逆时针方向