The Collaborative International Dictionary of English v.0.48:

Vampire \Vam"pire\, n. [F. vampire (cf. It. vampiro, G. & D.
   vampir), fr. Servian vampir.] [Written also vampyre.]
   1. A blood-sucking ghost; a soul of a dead person
      superstitiously believed to come from the grave and wander
      about by night sucking the blood of persons asleep, thus
      causing their death. This superstition was once prevalent
      in parts of Eastern Europe, and was especially current in
      Hungary about the year 1730. The vampire was often said to
      have the ability to transform itself into the form of a
      bat, as presented in the novel depicting the legend of
      Dracula published by Bram Stoker in 1897, which has
      inspired several movies.
      [1913 Webster + PJC]

            The persons who turn vampires are generally wizards,
            witches, suicides, and persons who have come to a
            violent end, or have been cursed by their parents or
            by the church,                        --Encyc. Brit.
      [1913 Webster]

   2. Fig.: One who lives by preying on others; an extortioner;
      a bloodsucker.
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   3. (Zool.) Either one of two or more species of South
      American blood-sucking bats belonging to the genera
      Desmodus and Diphylla; also called vampire bat.
      These bats are destitute of molar teeth, but have strong,
      sharp cutting incisors with which they make punctured
      wounds from which they suck the blood of horses, cattle,
      and other animals, as well as man, chiefly during sleep.
      They have a caecal appendage to the stomach, in which the
      blood with which they gorge themselves is stored.
      [1913 Webster]

   4. (Zool.) Any one of several species of harmless tropical
      American bats of the genus Vampyrus, especially
      Vampyrus spectrum. These bats feed upon insects and
      fruit, but were formerly erroneously supposed to suck the
      blood of man and animals. Called also false vampire.
      [1913 Webster]

   Vampire bat (Zool.), a vampire, 3.
      [1913 Webster]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

False \False\, a. [Compar. Falser; superl. Falsest.] [L.
   falsus, p. p. of fallere to deceive; cf. OF. faus, fals, F.
   faux, and AS. fals fraud. See Fail, Fall.]
   1. Uttering falsehood; unveracious; given to deceit;
      dishnest; as, a false witness.
      [1913 Webster]

   2. Not faithful or loyal, as to obligations, allegiance,
      vows, etc.; untrue; treacherous; perfidious; as, a false
      friend, lover, or subject; false to promises.
      [1913 Webster]

            I to myself was false, ere thou to me. --Milton.
      [1913 Webster]

   3. Not according with truth or reality; not true; fitted or
      likely to deceive or disappoint; as, a false statement.
      [1913 Webster]

   4. Not genuine or real; assumed or designed to deceive;
      counterfeit; hypocritical; as, false tears; false modesty;
      false colors; false jewelry.
      [1913 Webster]

            False face must hide what the false heart doth know.
                                                  --Shak.
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   5. Not well founded; not firm or trustworthy; erroneous; as,
      a false claim; a false conclusion; a false construction in
      grammar.
      [1913 Webster]

            Whose false foundation waves have swept away.
                                                  --Spenser.
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   6. Not essential or permanent, as parts of a structure which
      are temporary or supplemental.
      [1913 Webster]

   7. (Mus.) Not in tune.
      [1913 Webster]

   False arch (Arch.), a member having the appearance of an
      arch, though not of arch construction.

   False attic, an architectural erection above the main
      cornice, concealing a roof, but not having windows or
      inclosing rooms.

   False bearing, any bearing which is not directly upon a
      vertical support; thus, the weight carried by a corbel has
      a false bearing.

   False cadence, an imperfect or interrupted cadence.

   False conception (Med.), an abnormal conception in which a
      mole, or misshapen fleshy mass, is produced instead of a
      properly organized fetus.

   False croup (Med.), a spasmodic affection of the larynx
      attended with the symptoms of membranous croup, but
      unassociated with the deposit of a fibrinous membrane.

   False door or False window (Arch.), the representation of
      a door or window, inserted to complete a series of doors
      or windows or to give symmetry.

   False fire, a combustible carried by vessels of war,
      chiefly for signaling, but sometimes burned for the
      purpose of deceiving an enemy; also, a light on shore for
      decoying a vessel to destruction.

   False galena. See Blende.

   False imprisonment (Law), the arrest and imprisonment of a
      person without warrant or cause, or contrary to law; or
      the unlawful detaining of a person in custody.

   False keel (Naut.), the timber below the main keel, used to
      serve both as a protection and to increase the shio's
      lateral resistance.

   False key, a picklock.

   False leg. (Zool.) See Proleg.

   False membrane (Med.), the fibrinous deposit formed in
      croup and diphtheria, and resembling in appearance an
      animal membrane.

   False papers (Naut.), documents carried by a ship giving
      false representations respecting her cargo, destination,
      etc., for the purpose of deceiving.

   False passage (Surg.), an unnatural passage leading off
      from a natural canal, such as the urethra, and produced
      usually by the unskillful introduction of instruments.

   False personation (Law), the intentional false assumption
      of the name and personality of another.

   False pretenses (Law), false representations concerning
      past or present facts and events, for the purpose of
      defrauding another.

   False rail (Naut.), a thin piece of timber placed on top of
      the head rail to strengthen it.

   False relation (Mus.), a progression in harmony, in which a
      certain note in a chord appears in the next chord prefixed
      by a flat or sharp.

   False return (Law), an untrue return made to a process by
      the officer to whom it was delivered for execution.

   False ribs (Anat.), the asternal rebs, of which there are
      five pairs in man.

   False roof (Arch.), the space between the upper ceiling and
      the roof. --Oxford Gloss.

   False token, a false mark or other symbol, used for
      fraudulent purposes.

   False scorpion (Zool.), any arachnid of the genus
      Chelifer. See Book scorpion.

   False tack (Naut.), a coming up into the wind and filling
      away again on the same tack.

   False vampire (Zool.), the Vampyrus spectrum of South
      America, formerly erroneously supposed to have
      blood-sucking habits; -- called also vampire, and ghost
      vampire. The genuine blood-sucking bats belong to the
      genera Desmodus and Diphylla. See Vampire.

   False window. (Arch.) See False door, above.

   False wing. (Zool.) See Alula, and Bastard wing, under
      Bastard.

   False works (Civil Engin.), construction works to
      facilitate the erection of the main work, as scaffolding,
      bridge centering, etc.
      [1913 Webster]

WordNet (r) 3.0 (2006):

false vampire
    n 1: any New or Old World carnivorous bat erroneously thought to
         suck blood but in fact feeding on insects [syn: false
         vampire, false vampire bat]