Source : Webster's Revised Unabridged Dictionary (1913)

Tragedian \Tra*ge"di*an\, n. [Cf. F. trag['e]dien.]
   1. A writer of tragedy.

            Thence what the lofty, grave, tragedians taught.
                                                  --Milton.

   2. An actor or player in tragedy. --Shak.

Source : WordNet®

tragedian
     n 1: a writer (especially a playwright) who writes tragedies
     2: an actor who specializes in tragic roles