The Collaborative International Dictionary of English v.0.48:

Feathering \Feath"er*ing\, n.
   1. (Arch.) Same as Foliation.
      [1913 Webster]

   2. The act of turning the blade of the oar, as it rises from
      the water in rowing, from a vertical to a horizontal
      position. See To feather an oar, under Feather, v. t.
      [1913 Webster]

   3. A covering of feathers.
      [1913 Webster]

   Feathering float (Naut.), the float or paddle of a
      feathering wheel.

   Feathering screw (Naut.), a screw propeller, of which the
      blades may be turned so as to move edgewise through the
      water when the vessel is moving under sail alone.

   Feathering wheel (Naut.), a paddle wheel whose floats turn
      automatically so as to dip about perpendicularly into the
      water and leave in it the same way, avoiding beating on
      the water in the descent and lifting water in the ascent.
      [1913 Webster]