Source : Webster's Revised Unabridged Dictionary (1913)

Taj Mahal \Taj Ma*hal"\ (t[aum]j m[.a]*h[aum]l"). [Corruption of
   Per. Mumt[=a]z-i-Ma[.h]al, lit., the distinguished one of the
   palace, fr. Ar.]
   A marble mausoleum built at Agra, India, by the Mogul Emperor
   Shah Jahan, in memory of his favorite wife. In beauty of
   design and rich decorative detail it is one of the best
   examples of Saracenic architecture.

Source : WordNet®

Taj Mahal
     n : beautiful mausoleum at Agra built by the Mogul emperor Shah
         Jahan (completed in 1649) in memory of his favorite wife