The Collaborative International Dictionary of English v.0.48:

Fireman \Fire"man\, n.; pl. Firemen (-men).
   1. A man whose business is to extinguish fires in towns; a
      member of a fire company.
      [1913 Webster]

   2. A man who tends the fires, as of a steam engine; a
      stocker.
      [1913 Webster]

WordNet (r) 3.0 (2006):

fireman
    n 1: play in which children pretend to put out a fire
    2: a laborer who tends fires (as on a coal-fired train or
       steamship) [syn: stoker, fireman]
    3: a pitcher who does not start the game [syn: reliever,
       relief pitcher, fireman]
    4: a member of a fire department who tries to extinguish fires
       [syn: fireman, firefighter, fire fighter, fire-eater]