rudder

n. a flat piece of wood or metal at the back of a boat that moves to change its direction.

n. a vertical blade or vane at the stern of a vessel, controlled by a tiller or wheel, used to provide steering through water resistance.

“The captain turned the wheel, moving the rudder to steer the ship into the harbour.”

“The ship lost all steering capability after the rudder was damaged by a submerged reef during the storm.”

n. a movable part on the tail of an airplane used to turn the nose left or right.

n. a movable control surface attached to the vertical stabiliser of an aircraft, used to control yaw.

“The pilot used the foot pedals to move the rudder during the crosswind landing.”

“Modern fly-by-wire systems automatically coordinate the rudder movements with the ailerons to ensure a smooth turn.”

Technical

n. something that helps a person or organization stay on the right path or make decisions.

n. a metaphorical guide or governing principle that determines the course of an individual, group, or project.

“Without a clear plan, the new company felt like a ship without a rudder.”

“His strong ethical convictions served as a rudder throughout his turbulent political career, keeping him focused on his original goals.”

Literary