The Collaborative International Dictionary of English v.0.48:

Intestine \In*tes"tine\, a. [L. intestinus, fr. intus on the
   inside, within, fr. in in: cf. F. intestine. See In.]
   [1913 Webster]
   1. Internal; inward; -- opposed to external.
      [1913 Webster]

            Epilepsies, fierce catarrhs,
            Intestine stone and ulcers.           --Milton.
      [1913 Webster]

   2. Internal with regard to a state or country; domestic; not
      foreign; -- applied usually to that which is evil; as,
      intestine disorders, calamities, etc.
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            Hoping here to end
            Intestine war in heaven, the arch foe subdued.
                                                  --Milton.
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            An intestine struggle . . . between authority and
            liberty.                              --Hume.
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   3. Depending upon the internal constitution of a body or
      entity; subjective.
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            Everything labors under an intestine necessity.
                                                  --Cudworth.
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   4. Shut up; inclosed. [R.] --Cowper.
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The Collaborative International Dictionary of English v.0.48:

Intestine \In*tes"tine\, n.; pl. Intestines. [L. intestinum:
   cf. F. intestin. See Intestine, a.]
   [1913 Webster]
   1. (Anat.) That part of the alimentary canal between the
      stomach and the anus. See Illust. of Digestive apparatus.
      [1913 Webster]

   2. pl. The bowels; entrails; viscera.
      [1913 Webster]

   Large intestine (Human Anat. & Med.), the lower portion of
      the bowel, terminating at the anus. It is adapted for the
      retention of fecal matter, being shorter, broader, and
      less convoluted than the small intestine; it consists of
      three parts, the c[ae]cum, colon, and rectum.

   Small intestine (Human Anat. & Med.), the upper portion of
      the bowel, in which the process of digestion is
      practically completed. It is narrow and contorted, and
      consists of three parts, the duodenum, jejunum, and ileum.
      [1913 Webster]

WordNet (r) 3.0 (2006):

intestine
    n 1: the part of the alimentary canal between the stomach and
         the anus [syn: intestine, bowel, gut]

Moby Thesaurus II by Grady Ward, 1.0:

78 Moby Thesaurus words for "intestine":
   Eustachian tube, Fallopian tube, abatis, abdomen, anus, bowels,
   brain, brains, canal, cecum, chitterlings, cockscomb, colon, duct,
   duodenum, emunctory, endocardium, entrails, fistula, foregut,
   giblets, gizzard, guts, haslet, heart, hindgut, home, inland,
   innards, inner mechanism, inside, insides, interior, internal,
   internals, intestines, inward, inwards, jejunum, kidney, kidneys,
   kishkes, large intestine, liver, liver and lights, lung, marrow,
   meatus, midgut, municipal, national, native, ostium, oviduct,
   perineum, pore, pump, pylorus, rectum, salpinx, small intestine,
   spleen, stomach, sweetbread, thoracic duct, ticker, tongue, tripe,
   tripes, ureter, urethra, vagina, vas, vermiform appendix, vessel,
   viscera, vitals, works