The Collaborative International Dictionary of English v.0.48:

Cave \Cave\ (k[=a]v), n. [F. cave, L. cavus hollow, whence cavea
   cavity. Cf. Cage.]
   1. A hollow place in the earth, either natural or artificial;
      a subterraneous cavity; a cavern; a den.
      [1913 Webster]

   2. Any hollow place, or part; a cavity. [Obs.] "The cave of
      the ear." --Bacon.
      [1913 Webster]

   3. (Eng. Politics) A coalition or group of seceders from a
      political party, as from the Liberal party in England in
      1866. See Adullam, Cave of, in the Dictionary of Noted
      Names in Fiction.
      [Webster 1913 Suppl.]

   Cave bear (Zool.), a very large fossil bear (Ursus
      spel[ae]us) similar to the grizzly bear, but large;
      common in European caves.

   Cave dweller, a savage of prehistoric times whose dwelling
      place was a cave. --Tylor.

   Cave hyena (Zool.), a fossil hyena found abundanty in
      British caves, now usually regarded as a large variety of
      the living African spotted hyena.

   Cave lion (Zool.), a fossil lion found in the caves of
      Europe, believed to be a large variety of the African
      lion.

   Bone cave. See under Bone.
      [1913 Webster]