The Collaborative International Dictionary of English v.0.48:

Pinion \Pin"ion\, n. (Zool.)
   A moth of the genus Lithophane, as Lithophane antennata,
   whose larva bores large holes in young peaches and apples.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pinion \Pin"ion\, n. [OF. pignon a pen, F., gable, pinion (in
   sense 5); cf. Sp. pi[~n]on pinion; fr. L. pinna pinnacle,
   feather, wing. See Pin a peg, and cf. Pen a feather,
   Pennat, Pennon.]
   1. A feather; a quill. --Shak.
      [1913 Webster]

   2. A wing, literal or figurative.
      [1913 Webster]

            Swift on his sooty pinions flits the gnome. --Pope.
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   3. The joint of bird's wing most remote from the body.
      --Johnson.
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   4. A fetter for the arm. --Ainsworth.
      [1913 Webster]

   5. (Mech.) A cogwheel with a small number of teeth, or
      leaves, adapted to engage with a larger wheel, or rack
      (see Rack); esp., such a wheel having its leaves formed
      of the substance of the arbor or spindle which is its
      axis.
      [1913 Webster]

   Lantern pinion. See under Lantern.

   Pinion wire, wire fluted longitudinally, for making the
      pinions of clocks and watches. It is formed by being drawn
      through holes of the shape required for the leaves or
      teeth of the pinions.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pinion \Pin"ion\, v. t. [imp. & p. p. Pinioned; p. pr. & vb.
   n. Pinioning.]
   1. To bind or confine the wings of; to confine by binding the
      wings. --Bacon.
      [1913 Webster]

   2. To disable by cutting off the pinion joint. --Johnson.
      [1913 Webster]

   3. To disable or restrain, as a person, by binding the arms,
      esp. by binding the arms to the body. --Shak.
      [1913 Webster]

            Her elbows pinioned close upon her hips. --Cowper.
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   4. Hence, generally, to confine; to bind; to tie up.
      "Pinioned up by formal rules of state." --Norris.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pinion
    n 1: a gear with a small number of teeth designed to mesh with a
         larger wheel or rack
    2: any of the larger wing or tail feathers of a bird [syn:
       flight feather, pinion, quill, quill feather]
    3: wing of a bird [syn: pennon, pinion]
    v 1: bind the arms of [syn: pinion, shackle]
    2: cut the wings off (of birds)

Moby Thesaurus II by Grady Ward, 1.0:

70 Moby Thesaurus words for "pinion":
   anchor, appendage, arm, bind, bough, branch, bridle, chain, crest,
   enchain, entrammel, fasten, feather, fetter, gyve, hackle, hamper,
   hand, handcuff, hobble, hog-tie, hopple, imp, joint, lash, leash,
   leg, limb, link, lobe, lobule, make fast, manacle, member, moor,
   offshoot, organ, panache, peg down, picket, pin down, plume,
   plumule, put in irons, quill, ramification, restrain, rope, runner,
   scapular, scion, secure, shackle, spray, sprig, spur, straitjacket,
   strap, switch, tail, tendril, tether, tie, tie down, tie up,
   topknot, trammel, tuft, twig, wing