The Collaborative International Dictionary of English v.0.48:

Scorpion \Scor"pi*on\, n. [F., fr. L. scorpio, scorpius, Gr. ?,
   perhaps akin to E. sharp.]
   1. (Zool.) Any one of numerous species of pulmonate arachnids
      of the order Scorpiones, having a suctorial mouth, large
      claw-bearing palpi, and a caudal sting.
      [1913 Webster]

   Note: Scorpions have a flattened body, and a long, slender
         post-abdomen formed of six movable segments, the last
         of which terminates in a curved venomous sting. The
         venom causes great pain, but is unattended either with
         redness or swelling, except in the axillary or inguinal
         glands, when an extremity is affected. It is seldom if
         ever destructive of life. Scorpions are found widely
         dispersed in the warm climates of both the Old and New
         Worlds.
         [1913 Webster]

   2. (Zool.) The pine or gray lizard (Sceloporus undulatus).
      [Local, U. S.]
      [1913 Webster]

   3. (Zool.) The scorpene.
      [1913 Webster]

   4. (Script.) A painful scourge.
      [1913 Webster]

            My father hath chastised you with whips, but I will
            chastise you with scorpions.          --1 Kings xii.
                                                  11.
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   5. (Astron.) A sign and constellation. See Scorpio.
      [1913 Webster]

   6. (Antiq.) An ancient military engine for hurling stones and
      other missiles.
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   Book scorpion. (Zool.) See under Book.

   False scorpion. (Zool.) See under False, and Book
      scorpion.

   Scorpion bug, or Water scorpion (Zool.) See Nepa.

   Scorpion fly (Zool.), a neuropterous insect of the genus
      Panorpa. See Panorpid.

   Scorpion grass (Bot.), a plant of the genus Myosotis.
      Myosotis palustris is the forget-me-not.

   Scorpion senna (Bot.), a yellow-flowered leguminous shrub
      (Coronilla Emerus) having a slender joined pod, like a
      scorpion's tail. The leaves are said to yield a dye like
      indigo, and to be used sometimes to adulterate senna.

   Scorpion shell (Zool.), any shell of the genus Pteroceras.
      See Pteroceras.

   Scorpion spiders. (Zool.), any one of the Pedipalpi.

   Scorpion's tail (Bot.), any plant of the leguminous genus
      Scorpiurus, herbs with a circinately coiled pod; -- also
      called caterpillar.

   Scorpion's thorn (Bot.), a thorny leguminous plant
      (Genista Scorpius) of Southern Europe.

   The Scorpion's Heart (Astron.), the star Antares in the
      constellation Scorpio.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Caterpillar \Cat"er*pil`lar\, n. [OE. catyrpel, corrupted fr.
   OF. chatepelouse, or cate pelue, fr. chate, F. chatte,
   she-cat, fem. of chat, L. catus + L. pilosus hairy, or F.
   pelu hairy, fr. L. pilus hair. See Cat, and Pile hair.]
   1. (Zool.) The larval state of a butterfly or any
      lepidopterous insect; sometimes, but less commonly, the
      larval state of other insects, as the sawflies, which are
      also called false caterpillars. The true caterpillars have
      three pairs of true legs, and several pairs of abdominal
      fleshy legs (prolegs) armed with hooks. Some are hairy,
      others naked. They usually feed on leaves, fruit, and
      succulent vegetables, being often very destructive, Many
      of them are popularly called worms, as the cutworm,
      cankerworm, army worm, cotton worm, silkworm.
      [1913 Webster]

   2. (Bot.) A plant of the genus Scorpiurus, with pods
      resembling caterpillars.
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   Caterpillar catcher, or Caterpillar eater (Zool.), a bird
      belonging to the family of Shrikes, which feeds on
      caterpillars. The name is also given to several other
      birds.

   Caterpillar hunter (Zool.), any species of beetles of the
      genus Callosoma and other allied genera of the family
      Carabid[ae] which feed habitually upon caterpillars.
      [1913 Webster]

WordNet (r) 3.0 (2006):

caterpillar
    n 1: a wormlike and often brightly colored and hairy or spiny
         larva of a butterfly or moth
    2: a large tracked vehicle that is propelled by two endless
       metal belts; frequently used for moving earth in construction
       and farm work [syn: Caterpillar, cat]

Moby Thesaurus II by Grady Ward, 1.0:

30 Moby Thesaurus words for "caterpillar":
   arachnid, arthropod, aurelia, beetle, bug, centipede, chilopod,
   chrysalis, cocoon, daddy longlegs, diplopod, fly, grub, harvestman,
   hexapod, insect, larva, maggot, millepede, millipede, mite, nymph,
   nympha, pupa, scorpion, spider, tarantula, tick, wiggler,
   wriggler



Easton's 1897 Bible Dictionary:

Caterpillar
   the consumer. Used in the Old Testament (1 Kings 8:37; 2 Chr.
   6:28; Ps. 78:46; Isa. 33:4) as the translation of a word (hasil)
   the root of which means "to devour" or "consume," and which is
   used also with reference to the locust in Deut. 28:38. It may
   have been a species of locust, or the name of one of the
   transformations through which the locust passes, locust-grub. It
   is also found (Ps. 105:34; Jer. 51:14, 27; R.V., "cankerworm")
   as the rendering of a different Hebrew word, _yelek_, a word
   elsewhere rendered "cankerworm" (q.v.), Joel 1:4; 2:25. (See LOCUST.)