The Collaborative International Dictionary of English v.0.48:

Fountain \Foun"tain\ (foun"t[i^]n), n. [F. fontaine, LL.
   fontana, fr. L. fons, fontis. See 2d Fount.]
   1. A spring of water issuing from the earth.
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   2. An artificially produced jet or stream of water; also, the
      structure or works in which such a jet or stream rises or
      flows; a basin built and constantly supplied with pure
      water for drinking and other useful purposes, or for
      ornament.
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   3. A reservoir or chamber to contain a liquid which can be
      conducted or drawn off as needed for use; as, the ink
      fountain in a printing press, etc.
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   4. The source from which anything proceeds, or from which
      anything is supplied continuously; origin; source.
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            Judea, the fountain of the gospel.    --Fuller.
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            Author of all being,
            Fountain of light, thyself invisible. --Milton.
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   Air fountain. See under Air.

   Fountain heead, primary source; original; first principle.
      --Young.

   Fountain inkstand, an inkstand having a continual supply of
      ink, as from elevated reservoir.

   Fountain lamp, a lamp fed with oil from an elevated
      reservoir.

   Fountain pen, a pen with a reservoir in the handle which
      furnishes a supply of ink.

   Fountain pump.
      (a) A structure for a fountain, having the form of a pump.
      (b) A portable garden pump which throws a jet, for
          watering plants, etc.

   Fountain shell (Zool.), the large West Indian conch shell
      (Strombus gigas).

   Fountain of youth, a mythical fountain whose waters were
      fabled to have the property of renewing youth.
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The Collaborative International Dictionary of English v.0.48:

Pen \Pen\ (p[e^]n), n. [OE. penne, OF. penne, pene, F. penne,
   fr. L. penna.]
   1. A feather. [Obs.] --Spenser.
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   2. A wing. [Obs.] --Milton.
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   3. An instrument used for writing with ink, formerly made of
      a reed, or of the quill of a goose or other bird, but now
      also of other materials, as of steel, gold, etc. Also,
      originally, a stylus or other instrument for scratching or
      graving.
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            Graven with an iron pen and lead in the rock. --Job
                                                  xix. 24.
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   4. Fig.: A writer, or his style; as, he has a sharp pen.
      "Those learned pens." --Fuller.
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   5. (Zool.) The internal shell of a squid.
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   6. [Etymol. uncertain.] (Zool.) A female swan; -- contrasted
      with cob, the male swan. [Prov. Eng.]
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   Bow pen. See Bow-pen.

   Dotting pen, a pen for drawing dotted lines.

   Drawing pen, or Ruling pen, a pen for ruling lines having
      a pair of blades between which the ink is contained.

   Fountain pen, Geometric pen. See under Fountain, and
      Geometric.

   Music pen, a pen having five points for drawing the five
      lines of the staff.

   Pen and ink, or pen-and-ink, executed or done with a pen
      and ink; as, a pen and ink sketch.

   Pen feather. A pin feather. [Obs.]

   Pen name. See under Name.

   Sea pen (Zool.), a pennatula. [Usually written sea-pen.]
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WordNet (r) 3.0 (2006):

fountain pen
    n 1: a pen that is supplied with ink from a reservoir in its
         barrel