rud·der·post /-ˌpost/
  舵軸,舵柱
  Rud·der·post n. Naut. The shank of a rudder, having the blade at one end and the attachments for operating it at the other.
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  rudderpost
       n : a vertical post at the forward edge of a rudder that enables
           the rudder to pivot [syn: rudderstock]