1. 
2. 
[syn: slipstream, airstream, race, backwash, wash]
The Collaborative International Dictionary of English v.0.48:
airstream \air"stream`\ n.
   1. a relatively well-defined prevailing wind.
      [WordNet 1.5]
   2. the flow of air that is driven backwards by an aircraft
      propeller.
   Syn: slipstream, race, backwash, wash
        [WordNet 1.5]
WordNet (r) 3.0 (2006):
airstream
    n 1: a relatively well-defined prevailing wind
    2: the flow of air that is driven backwards by an aircraft
       propeller [syn: slipstream, airstream, race,
       backwash, wash]