The Collaborative International Dictionary of English v.0.48:

Mahabarata \Ma*ha*ba"ra*ta\, Mahabharatam \Ma*ha*bha"ra*tam\, n.
   [Skr. mah[=a]bh[=a]rata.] (Hinduism)
   A celebrated sacred epic poem of the Hindus, written in
   Sanskrit. It is of great length, and is chiefly devoted to a
   history, in many episodes, of a civil war between two
   dynasties of ancient India.

   Syn: Mahabharatam, Mahabharatum.
        [1913 Webster]

WordNet (r) 3.0 (2006):

Mahabharatam
    n 1: (Hinduism) a sacred epic Sanskrit poem of India dealing in
         many episodes with the struggle between two rival families
         [syn: Mahabharata, Mahabharatam, Mahabharatum]