The Collaborative International Dictionary of English v.0.48:

Kaaba \Ka*a"ba\ (k[.a]*[=a]"b[.a]), prop. n. [Ar. ka'bah, lit.,
   a square building, fr. ka'b cube.]
   The small and nearly cubical stone building, in the court of
   the Great Mosque at Mecca, toward which all Mohammedans must
   pray. It contains a sacred black stone, believed by
   Mohammedans to be one of the precious stones of paradise, and
   to have been brought to Abraham when he was contructing the
   Kaaba, by the Angel Gabriel. The Kaaba itself predates
   Mohammed, having been a pantheon which contained Arab idols,
   which were destroyed by Mohammed. [Written also caaba,
   kaabeh and kaabah.]
   [1913 Webster +PJC]