Source : Webster's Revised Unabridged Dictionary (1913)

Imam \I*mam"\, Iman \I*man"\, Imaum \I*maum"\, n. [Ar. im[=a]m.]
   1. Among the Mohammedans, a minister or priest who performs
      the regular service of the mosque.

   2. A Mohammedan prince who, as a successor of Mohammed,
      unites in his person supreme spiritual and temporal power.

Source : WordNet®

imaum
     n : (Islam) the man who leads prayers in a mosque; for Shiites
         an imam is a recognized authority on Islamic theology and
         law and a spiritual guide [syn: {imam}]