Meaningcylinder · gun barrel · pipe · sleeve · tubeOn'yomiトウKun'yomiつつCommon compounds (8)封筒 ふうとうenvelope筒井 つついround well円筒 えんとうcylinder気筒 きとうcylinder井筒 いづつfamily crest design based on a square wooden well curb水筒 すいとうcanteen; flask; water bottle; thermos発煙筒 はつえんとうsmoke bomb; smoke candle筒抜け つつぬけgoing in one ear and out the other