Source : Webster's Revised Unabridged Dictionary (1913)

Helm \Helm\, v. t.
   To cover or furnish with a helm or helmet. [Perh. used only
   as a past part. or part. adj.]

         She that helmed was in starke stours.    --Chaucer.

Helm \Helm\, v. t. [imp. & p. p. {Helmed}; p. pr. & vb. n.
   {Helming}.]
   To steer; to guide; to direct. [R.]

         The business he hath helmed.             --Shak.

         A wild wave . . . overbears the bark, And him that
         helms it.                                --Tennyson.

Helm \Helm\, n.
   See {Haulm}, straw.

Helm \Helm\, n. [OE. helme, AS. helma rudder; akin to D. & G.
   helm, Icel. hj[=a]lm, and perh. to E. helve.]
   1. (Naut.) The apparatus by which a ship is steered,
      comprising rudder, tiller, wheel, etc.; -- commonly used
      of the tiller or wheel alone.

   2. The place or office of direction or administration. ``The
      helm of the Commonwealth.'' --Melmoth.

   3. One at the place of direction or control; a steersman;
      hence, a guide; a director.

            The helms o' the State, who care for you like
            fathers.                              --Shak.

   4. [Cf. {Helve}.] A helve. [Obs. or Prov. Eng.]

   {Helm amidships}, when the tiller, rudder, and keel are in
      the same plane.

   {Helm aport}, when the tiller is borne over to the port side
      of the ship.

   {Helm astarboard}, when the tiller is borne to the starboard
      side.

   {Helm alee}, {Helm aweather}, when the tiller is borne over
      to the lee or to the weather side.

   {Helm hard alee} or {hard aport}, {hard astarboard}, etc.,
      when the tiller is borne over to the extreme limit.

   {Helm port}, the round hole in a vessel's counter through
      which the rudderstock passes.

   {Helm down}, helm alee.

   {Helm up}, helm aweather.

   {To ease the helm}, to let the tiller come more amidships, so
      as to lessen the strain on the rudder.

   {To feel the helm}, to obey it.

   {To right the helm}, to put it amidships.

   {To shift the helm}, to bear the tiller over to the
      corresponding position on the opposite side of the vessel.
      --Ham. Nav. Encyc.

Helm \Helm\, n. [AS. See {Helmet}.]
   1. A helmet. [Poetic]

   2. A heavy cloud lying on the brow of a mountain. [Prov.
      Eng.] --Halliwell.

Source : WordNet®

helm
     n 1: steering mechanism for a vessel; a mechanical device by
          which a vessel is steered
     2: a position of leadership; "the President is at the helm of
        the Ship of State"