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]

Moby Thesaurus II by Grady Ward, 1.0:

24 Moby Thesaurus words for "airman":
   aeronaut, aeroplaner, aeroplanist, air pilot, airplanist,
   astronaut, aviator, barnstormer, birdman, captain, cloud seeder,
   commercial pilot, copilot, crop-duster, flier, instructor,
   jet jockey, licensed pilot, pilot, rainmaker, stunt flier,
   stunt man, test pilot, wingman