The Collaborative International Dictionary of English v.0.48:

Airsick \Air"sick`\, a.
   Affected with air sickness or a["e]rial sickness; feeling
   nauseous due to riding in an airplane. -- Air"sick`ness, n.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

airsick
    adj 1: experiencing motion sickness [syn: airsick, air sick,
           carsick, seasick]