筒 - cylinder, pipe, tube

cylinder

envelope

round well

canteen; flask; water bottle; thermos

smoke bomb; smoke candle

cylinder

pipe; tube; cylinder

container made by cutting a piece of bamboo lengthways; bamboo tube; bamboo cylinder

cylindrical; tubular

grenade launcher

tight sleeve (of a kimono or dress)

being heard (by others); being overheard; being leaked (of plans, secrets, etc.)