The Collaborative International Dictionary of English v.0.48:

caesar \c[ae]"sar\ (s[=e]"z[~e]r), n. [L.]
   A Roman emperor, as being the successor of Augustus C[ae]sar.
   Hence, a kaiser, or emperor of Germany, or any emperor or
   powerful ruler. See Kaiser, Kesar, Tsar.
   [1913 Webster]

         Marlborough anticipated the day when he would be
         servilely flattered and courted by C[ae]sar on one side
         and by Louis the Great on the other.     --Macaulay.
   [1913 Webster] C[ae]sarean

WordNet (r) 3.0 (2006):

Caesar
    n 1: conqueror of Gaul and master of Italy (100-44 BC) [syn:
         Caesar, Julius Caesar, Gaius Julius Caesar]
    2: United States comedian who pioneered comedy television shows
       (born 1922) [syn: Caesar, Sid Caesar, Sidney Caesar]