[1] : The Collaborative International Dictionary of English v.0.48

vermin \ver"min\, n. sing.  pl.; used chiefly as plural. oe.
   vermine, f. vermine, from l. vermis a worm; cf. ll. vermen a
   worm, l. verminosus full of worms. see vermicular, worm.
   1. an animal, in general. obs.
      1913 webster

            wherein were all manner of fourfooted beasts of the
            earth, and vermin, and worms, and fowls. --acts x.
                                                  12. geneva
                                                  bible.
      1913 webster

            this crocodile is a mischievous fourfooted beast, a
            dangerous vermin, used to both elements. --holland.
      1913 webster

   2. a noxious or mischievous animal; especially, noxious
      little animals or insects, collectively, as squirrels,
      rats, mice, worms, flies, lice, bugs, etc. "cruel hounds
      or some foul vermin." --chaucer.
      1913 webster

            great injuries these vermin, mice and rats, do in
            the field.                            --mortimer.
      1913 webster

            they disdain such vermin when the mighty boar of the
            forest . . . is before them.          --burke.
      1913 webster

   3. hence, in contempt, noxious human beings.
      1913 webster

            you are my prisoners, base vermin.    --hudibras.
      1913 webster
see also:
vermicular worm 

[2] : WordNet (r) 2.0

vermin
     n 1: an irritating or obnoxious person syn: varmint
     2: any of various small animals or insects that are pests; e.g.
        cockroaches or rats
see also:
varmint 

[3] : Moby Thesaurus II by Grady Ward, 1.0

56 moby thesaurus words for "vermin":
   amphibian, animal, aquatic, beast, biped, canine, cannibal,
   carnivore, cattle, chaff, cosmopolite, cur, dog, dregs,
   dregs of society, feline, gnawer, herbivore, hound, hyena, insect,
   insectivore, invertebrate, mammal, mammalian, marsupial,
   marsupialian, mongrel, offscourings, offscum, omnivore, pig,
   polecat, primate, quadruped, raff, reptile, riffraff, rodent,
   rubbish, ruminant, scavenger, scum, serpent, skunk, snake, sordes,
   swine, swinish multitude, trash, ungulate, varmint, vertebrate,
   viper, whelp, worm

Vermin >> V Words
Vermin, definition of term: Vermin
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