防ぼう空くうTop 20000MeaningsNoun1. air defense; air defenceKanji used防prevent空empty airPitch accentぼうくうUsed in vocabulary防ぼう空くう壕ごうair-raid shelter; bomb shelterNoun防ぼう空くう砲ほうair defense artillery; air defence artilleryNoun防ぼう空くう頭ず巾きんair-raid hoodNoun防ぼう空くう気き球きゅうbarrage balloonNoun防ぼう空くう識しき別べつ圏けんair defense identification zone; ADIZNoun