an·ti·air·craft /-ˈærˌkræft, ˈɛr-/
  (a.)對付飛機的,對空的,防空的
  antiaircraft
       adj : designed for defense from a surface position against air
             attack
       n : artillery designed to shoot upward at airplanes [syn: antiaircraft
           gun, flak, flack, pom-pom, ack-ack, ack-ack gun]