pom-pom

pom-pom (http://definr.com/pom-pom)

     n 1: decoration consisting of a ball of tufted wool or silk;
          usually worn on a hat [syn: pompon]
     2: artillery designed to shoot upward at airplanes [syn: antiaircraft,
         antiaircraft gun, flak, flack, ack-ack, {ack-ack
        gun}]