The Collaborative International Dictionary of English v.0.48:

Airman \Air"man\, n.
   1. A man who ascends or flies in an aircraft; an aviator; an
      airplane pilot.
      [Webster 1913 Suppl.]

   2. an enlisted man in the air force; there are several
      grades.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

airman
    n 1: someone who operates an aircraft [syn: aviator,
         aeronaut, airman, flier, flyer]