筒 cylinder, pipe, tube, gun barrel, sleeve 12 strokes jōyō, taught in secondary school old JLPT 2 #1631 in newspapers Readings Onトウ Kunつつ In Chinese 筒 Words written with it 封筒 ふうとう envelope N5 筒井 つつい round well 水筒 すいとう canteen N2 筒 つつ pipe N1 円筒 えんとう cylinder 気筒 きとう cylinder 井筒 いづつ well curb 発煙筒 はつえんとう smoke bomb 筒抜け つつぬけ being heard (by others)