The Collaborative International Dictionary of English v.0.48:

Quill \Quill\, n. [Perhaps fr. F. quille ninepin (see
   Kayless); but cf. also G. kiel a quill. MHG. kil, and Ir.
   cuille a quill.]
   1. One of the large feathers of a bird's wing, or one of the
      rectrices of the tail; also, the stock of such a feather.
      [1913 Webster]

   2. A pen for writing made by sharpening and splitting the
      point or nib of the stock of a feather; as, history is the
      proper subject of his quill. --Sir H. Wotton.
      [1913 Webster]

   3. (Zool.)
      (a) A spine of the hedgehog or porcupine.
      (b) The pen of a squid. See Pen.
          [1913 Webster]

   4. (Mus.)
      (a) The plectrum with which musicians strike the strings
          of certain instruments.
      (b) The tube of a musical instrument.
          [1913 Webster]

                He touched the tender stops of various quills.
                                                  --Milton.
          [1913 Webster]

   5. Something having the form of a quill; as:
      (a) The fold or plain of a ruff.
      (b) (Weaving) A spindle, or spool, as of reed or wood,
          upon which the thread for the woof is wound in a
          shuttle.
      (c) (Mach.) A hollow spindle.
          [1913 Webster]

   6. (Pharm.) A roll of dried bark; as, a quill of cinnamon or
      of cinchona.
      [Webster 1913 Suppl.]

   Quill bit, a bit for boring resembling the half of a reed
      split lengthways and having its end sharpened like a
      gouge.

   Quill driver, one who works with a pen; a writer; a clerk.
      [Jocose]

   Quill nib, a small quill pen made to be used with a holder.
      --Simmonds.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Quill \Quill\, v. t. [imp. & p. p. Quilled; p. pr. & vb. n.
   Quilling.]
   1. To plaint in small cylindrical ridges, called quillings;
      as, to quill a ruffle.
      [1913 Webster]

            His cravat seemed quilled into a ruff. --Goldsmith.
      [1913 Webster]

   2. To wind on a quill, as thread or yarn. --Judd.
      [1913 Webster]

WordNet (r) 3.0 (2006):

quill
    n 1: pen made from a bird's feather [syn: quill, quill pen]
    2: a stiff hollow protective spine on a porcupine or hedgehog
    3: any of the larger wing or tail feathers of a bird [syn:
       flight feather, pinion, quill, quill feather]
    4: the hollow spine of a feather [syn: quill, calamus,
       shaft]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "quill":
   barb, barbule, barrel, bramble, brier, bristle, burr, cactus,
   catchweed, cilium, cleavers, crest, feather, filament, filamentule,
   goose grass, hackle, needle, nettle, panache, pine needle, pinion,
   plume, plumule, prickle, scapular, shaft, spicule, spiculum, spike,
   spikelet, spine, sticker, thistle, thorn, topknot, tuft, yucca



The Devil's Dictionary (1881-1906):

QUILL, n.  An implement of torture yielded by a goose and commonly
wielded by an ass.  This use of the quill is now obsolete, but its
modern equivalent, the steel pen, is wielded by the same everlasting
Presence.