The Collaborative International Dictionary of English v.0.48:

Aerodynamic \Aer`o*dy*nam"ic\, Aerodynamic
\A`["e]r*o*dy*nam"ic\, a.
   1. Pertaining to the force of air in motion.
      [1913 Webster]

   2. having a shape designed to minimize wind resistance
      (aerodynamic drag) when moving through the air or other
      gas; -- used especially of vehicles; as, the aerodynamic
      styling of an automobile.
      [PJC]

WordNet (r) 3.0 (2006):

aerodynamic
    adj 1: of or relating to aerodynamics
    2: designed or arranged to offer the least resistant to fluid
       flow; "a streamlined convertible" [syn: streamlined,
       aerodynamic, flowing, sleek]