What is "weather helm"

Weather \Weath"er\, a. (Naut.) Being toward the wind, or windward -- opposed to lee; as, weather bow, weather braces, weather gauge, weather lifts, weather quarter, weather shrouds, etc. Weather gauge.

1. (Naut.) The position of a ship to the windward of another.

2. Fig.: A position of advantage or superiority; advantage in position.

   To veer, and tack, and steer a cause Against the weather gauge of laws.
   --Hudibras.

   Weather helm (Naut.), a tendency on the part of a sailing vessel to come up into the wind, rendering it necessary to put the helm up, that is, toward the weather side.

   Weather shore (Naut.), the shore to the windward of a ship.
   --Totten.

   Weather tide (Naut.), the tide which sets against the lee side of a ship, impelling her to the windward.
   --Mar. Dict.

Weather helm is the tendency of sailing vessels to turn towards the source of wind, creating an unbalanced helm that requires pulling the tiller to windward (i.e. 'to weather') in order to counteract the effect. Weather helm is the opposite of lee helm.