The Collaborative International Dictionary of English v.0.48:

Gall \Gall\ (g[add]l), n.[OE. galle, gal, AS. gealla; akin to D.
   gal, OS. & OHG. galla, Icel. gall, SW. galla, Dan. galde, L.
   fel, Gr. ?, and prob. to E. yellow. [root]49. See Yellow,
   and cf. Choler]
   1. (Physiol.) The bitter, alkaline, viscid fluid found in the
      gall bladder, beneath the liver. It consists of the
      secretion of the liver, or bile, mixed with that of the
      mucous membrane of the gall bladder.
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   2. The gall bladder.
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   3. Anything extremely bitter; bitterness; rancor.
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            He hath . . . compassed me with gall and travail.
                                                  --Lam. iii. 5.
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            Comedy diverted without gall.         --Dryden.
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   4. Impudence; brazen assurance. [Slang]
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   Gall bladder (Anat.), the membranous sac, in which the
      bile, or gall, is stored up, as secreted by the liver; the
      cholecystis. See Illust. of Digestive apparatus.

   Gall duct, a duct which conveys bile, as the cystic duct,
      or the hepatic duct.

   Gall sickness, a remitting bilious fever in the
      Netherlands. --Dunglison.

   Gall of the earth (Bot.), an herbaceous composite plant
      with variously lobed and cleft leaves, usually the
      Prenanthes serpentaria.
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WordNet (r) 3.0 (2006):

gall bladder
    n 1: a muscular sac attached to the liver that stores bile
         (secreted by the liver) until it is needed for digestion
         [syn: gallbladder, gall bladder]