The Collaborative International Dictionary of English v.0.48:

Role \Role\, Role \R[^o]le\, n. [F. See Roll.]
   A part, or character, performed by an actor in a drama;
   hence, a part of function taken or assumed by any one; as, he
   has now taken the role of philanthropist.
   [1913 Webster]

   Title role, the part, or character, which gives the title
      to a play, as the part of Hamlet in the play of that name.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

59 Moby Thesaurus words for "role":
   actor, antagonist, antihero, bit, bit part, capacity, cast,
   character, condition, cue, duty, end use, fat part, feeder,
   function, heavy, hero, heroine, immediate purpose, impersonation,
   ingenue, job, lead, lead role, leading lady, leading man,
   leading woman, lines, office, operation, operational purpose, part,
   person, personage, piece, place, position, post, protagonist,
   province, purpose, quality, relation, responsibility, side,
   situation, soubrette, status, straight part, supporting character,
   supporting role, task, title role, ultimate purpose, use, villain,
   walk-on, walking part, work