The Collaborative International Dictionary of English v.0.48:

chairperson \chairperson\ n.
   the officer who presides at the meetings of an organization;
   -- same as chair[3] or chairman[1], but used to achieve a
   sex-neutral register.

   Syn: president, chairman, chairwoman, chair.
        [WordNet 1.5 +PJC]

WordNet (r) 3.0 (2006):

chairperson
    n 1: the officer who presides at the meetings of an
         organization; "address your remarks to the chairperson"
         [syn: president, chairman, chairwoman, chair,
         chairperson]