防ぼう空くう気き球きゅうぼうくうききゅうMeanings1nounbarrage balloonA large tethered balloon used as a defense against low-flying aircraft, especially during World War II. Also referred to as 阻塞気球.See also: 阻塞気球第だい二に次じ世せ界かい大たい戦せん中ちゅう、ロンドン上じょう