The Collaborative International Dictionary of English v.0.48:

dragon \drag"on\ (dr[a^]g"[u^]n), n. [F. dragon, L. draco, fr.
   Gr. dra`kwn, prob. fr. de`rkesqai, dra`kein, to look (akin to
   Skr. dar[,c] to see), and so called from its terrible eyes.
   Cf. Drake a dragon, Dragoon.]
   1. (Myth.) A fabulous animal, generally represented as a
      monstrous winged serpent or lizard, with a crested head
      and enormous claws, and regarded as very powerful and
      ferocious.
      [1913 Webster]

            The dragons which appear in early paintings and
            sculptures are invariably representations of a
            winged crocodile.                     --Fairholt.
      [1913 Webster]

   Note: In Scripture the term dragon refers to any great
         monster, whether of the land or sea, usually to some
         kind of serpent or reptile, sometimes to land serpents
         of a powerful and deadly kind. It is also applied
         metaphorically to Satan.
         [1913 Webster]

               Thou breakest the heads of the dragons in the
               waters.                            -- Ps. lxxiv.
                                                  13.
         [1913 Webster]

               Thou shalt tread upon the lion and adder; the
               young lion and the dragon shalt thou trample
               under feet.                        -- Ps. xci.
                                                  13.
         [1913 Webster]

               He laid hold on the dragon, that old serpent,
               which is the Devil and Satan, and bound him a
               thousand years.                    --Rev. xx. 2.
         [1913 Webster]

   2. A fierce, violent person, esp. a woman. --Johnson.
      [1913 Webster]

   3. (Astron.) A constellation of the northern hemisphere
      figured as a dragon; Draco.
      [1913 Webster]

   4. A luminous exhalation from marshy grounds, seeming to move
      through the air as a winged serpent.
      [1913 Webster]

   5. (Mil. Antiq.) A short musket hooked to a swivel attached
      to a soldier's belt; -- so called from a representation of
      a dragon's head at the muzzle. --Fairholt.
      [1913 Webster]

   6. (Zool.) A small arboreal lizard of the genus Draco, of
      several species, found in the East Indies and Southern
      Asia. Five or six of the hind ribs, on each side, are
      prolonged and covered with weblike skin, forming a sort of
      wing. These prolongations aid them in making long leaps
      from tree to tree. Called also flying lizard.
      [1913 Webster]

   7. (Zool.) A variety of carrier pigeon.
      [1913 Webster]

   8. (Her.) A fabulous winged creature, sometimes borne as a
      charge in a coat of arms.
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   Note: Dragon is often used adjectively, or in combination, in
         the sense of relating to, resembling, or characteristic
         of, a dragon.
         [1913 Webster]

   Dragon arum (Bot.), the name of several species of
      Aris[ae]ma, a genus of plants having a spathe and
      spadix. See Dragon root(below).

   Dragon fish (Zool.), the dragonet.

   Dragon fly (Zool.), any insect of the family
      Libellulid[ae]. They have finely formed, large and
      strongly reticulated wings, a large head with enormous
      eyes, and a long body; -- called also mosquito hawks.
      Their larv[ae] are aquatic and insectivorous.

   Dragon root (Bot.), an American aroid plant (Aris[ae]ma
      Dracontium); green dragon.

   Dragon's blood, a resinous substance obtained from the
      fruit of several species of Calamus, esp. from Calamus
      Rotang and Calamus Draco, growing in the East Indies. A
      substance known as dragon's blood is obtained by exudation
      from Drac[ae]na Draco; also from Pterocarpus Draco, a
      tree of the West Indies and South America. The color is
      red, or a dark brownish red, and it is used chiefly for
      coloring varnishes, marbles, etc. Called also Cinnabar
      Gr[ae]corum.

   Dragon's head.
      (a) (Bot.) A plant of several species of the genus
          Dracocephalum. They are perennial herbs closely
          allied to the common catnip.
      (b) (Astron.) The ascending node of a planet, indicated,
          chiefly in almanacs, by the symbol ?. The deviation
          from the ecliptic made by a planet in passing from one
          node to the other seems, according to the fancy of
          some, to make a figure like that of a dragon, whose
          belly is where there is the greatest latitude; the
          intersections representing the head and tail; -- from
          which resemblance the denomination arises. --Encyc.
          Brit.

   Dragon shell (Zool.), a species of limpet.

   Dragon's skin, fossil stems whose leaf scars somewhat
      resemble the scales of reptiles; -- a name used by miners
      and quarrymen. --Stormonth.

   Dragon's tail (Astron.), the descending node of a planet,
      indicated by the symbol ?. See Dragon's head (above).

   Dragon's wort (Bot.), a plant of the genus Artemisia
      (Artemisia dracunculus).

   Dragon tree (Bot.), a West African liliaceous tree
      (Drac[ae]na Draco), yielding one of the resins called
      dragon's blood. See Drac[ae]na.

   Dragon water, a medicinal remedy very popular in the
      earlier half of the 17th century. "Dragon water may do
      good upon him." --Randolph (1640).

   Flying dragon, a large meteoric fireball; a bolide.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dragon
    n 1: a creature of Teutonic mythology; usually represented as
         breathing fire and having a reptilian body and sometimes
         wings [syn: dragon, firedrake]
    2: a fiercely vigilant and unpleasant woman [syn: dragon,
       tartar]
    3: a faint constellation twisting around the north celestial
       pole and lying between Ursa Major and Cepheus [syn: Draco,
       Dragon]
    4: any of several small tropical Asian lizards capable of
       gliding by spreading winglike membranes on each side of the
       body [syn: dragon, flying dragon, flying lizard]

Moby Thesaurus II by Grady Ward, 1.0:

136 Moby Thesaurus words for "dragon":
   Argus, Briareus, Cerberus, Charybdis, Cyclops, Echidna,
   Gila monster, Gorgon, Harpy, Hydra, Loch Ness monster, Mafioso,
   Medusa, Minotaur, Pegasus, Python, Scylla, Sphinx, Talos, Tartar,
   Typhon, Young Turk, agama, alligator, anole, bear, bearded lizard,
   beast, beldam, berserk, berserker, blindworm, bomber, box turtle,
   brute, butterfly agama, cayman, centaur, chameleon, chimera,
   cockatrice, crank, crocodile, crosspatch, demon, devil,
   diamondback, drake, false map turtle, feist, fiend, fire-eater,
   firebrand, flying dragon, fury, gavial, gecko,
   girdle-tailed lizard, glass snake, goon, gorilla, green turtle,
   griffin, grizzly bear, grouch, gunsel, hardnose, hawksbill,
   hawksbill turtle, hell-raiser, hellcat, hellhound, hellion,
   hippocampus, holy terror, hood, hoodlum, hothead, hotspur, iguana,
   incendiary, killer, leatherback, lizard, mad dog, madcap, matamata,
   mermaid, merman, monitor, monster, mugger, nixie, ogre, ogress,
   rapist, revolutionary, roc, salamander, satyr, savage, sea horse,
   sea serpent, sea turtle, she-wolf, siren, soft-shelled turtle,
   sorehead, spitfire, stump tail, teju, termagant, terrapin, terror,
   terrorist, tiger, tigress, tortoise, tough, tough guy, troll,
   tuatara, turtle, ugly customer, unicorn, vampire, violent, virago,
   vixen, werewolf, wild beast, windigo, witch, wolf, xiphopagus,
   zombie



The Jargon File (version 4.4.7, 29 Dec 2003):

dragon
 n.

    [MIT] A program similar to a daemon, except that it is not invoked at
    all, but is instead used by the system to perform various secondary tasks.
    A typical example would be an accounting program, which keeps track of who
    is logged in, accumulates load-average statistics, etc. Under ITS, many
    terminals displayed a list of people logged in, where they were, what they
    were running, etc., along with some random picture (such as a unicorn,
    Snoopy, or the Enterprise), which was generated by the ?name dragon?.
    Usage: rare outside MIT ? under Unix and most other OSes this would be
    called a background demon or daemon. The best-known Unix example of a
    dragon is cron(1). At SAIL, they called this sort of thing a phantom.


The Free On-line Dictionary of Computing (30 December 2018):

DRAGON

   1. An Esprit project aimed at providing effective support to
   reuse in real-time distributed Ada application
   programs.

   2. An implementation language used by BTI Computer Systems.

   E-mail: Pat Helland .

   [Jargon File]

   (1994-12-08)


The Free On-line Dictionary of Computing (30 December 2018):

dragon

   [MIT] A program similar to a daemon, except that it is not
   invoked at all, but is instead used by the system to perform
   various secondary tasks.  A typical example would be an
   accounting program, which keeps track of who is logged in,
   accumulates load-average statistics, etc.  Under ITS, many
   terminals displayed a list of people logged in, where they
   were, what they were running, etc., along with some random
   picture (such as a unicorn, Snoopy or the Enterprise), which
   was generated by the "name dragon".  Use is rare outside
   MIT, under Unix and most other operating systems this
   would be called a "background demon" or daemon.  The
   best-known Unix example of a dragon is cron.  At SAIL,
   they called this sort of thing a "phantom".

   [Jargon File]


Easton's 1897 Bible Dictionary:

Dragon
   (1.) Heb. tannim, plural of tan. The name of some unknown
   creature inhabiting desert places and ruins (Job 30:29; Ps.
   44:19; Isa. 13:22; 34:13; 43:20; Jer. 10:22; Micah 1:8; Mal.
   1:3); probably, as translated in the Revised Version, the jackal
   (q.v.).

     (2.) Heb. tannin. Some great sea monster (Jer. 51:34). In Isa.
   51:9 it may denote the crocodile. In Gen. 1:21 (Heb. plural
   tanninim) the Authorized Version renders "whales," and the
   Revised Version "sea monsters." It is rendered "serpent" in Ex.
   7:9. It is used figuratively in Ps. 74:13; Ezek. 29:3.

     In the New Testament the word "dragon" is found only in Rev.
   12:3, 4, 7, 9, 16, 17, etc., and is there used metaphorically of
   "Satan." (See WHALE.)