1) Post 2) Rudderstock 1) Rudderstock 
• (n.) The shank of a rudder, having the blade at one end and the attachments for operating it at the other.
Rud'der·post noun (Nautical) The shank of a rudder, having the blade at one end and the attachments for operating it at the other. 
[n] - a vertical post at the forward edge of a rudder that enables the rudder to pivot
rudderstock noun a vertical post at the forward edge of a rudder that enables the rudder to pivot
the vertical member of a stern frame on which the rudder is hung; a sternpost.