筒

Phono-semantic compound:

筒 = 竹 (“bamboo,” semantic) + 同 (“same; together,” phonetic)

竹 implies objects made of bamboo, or bamboo-like hollow forms.

同 gives the sound (duwng / 통) and hints at internal uniformity → cylinder.

In early usage, 筒 referred specifically to a bamboo tube, used for storing arrows, liquids, or documents.

From there it extended to:

• pipes, cylinders, hollow containers

• cylindrical shapes of any material (wood, metal, etc.)

氣筒 (기통) — air pump; cylinder

筒形 (통형) — cylindrical shape

筆筒 (필통) — pencil holder

藥筒 (약통) — pill cylinder / medicine tube

水筒 (수통) — water canteen (historical/military)

탄약통 (not always written in Hanja, but possible: 彈藥筒) — ammo tube

Note on 桶 vs. 筒:

Both are read 통 in Korean but differ:

筒 — tube, cylinder (hollow, usually long)

桶 — bucket, barrel (container with capacity/volume)

Shape emphasis:

筒 emphasizes uniform cylindrical shape, while 管 emphasizes tube for passage (pipe).

Historical bamboo usage:

Bamboo’s natural hollowness made it the universal material for early containers, influencing many “bamboo-radical” characters related to containers and writing.

Classical citations:

後漢書·輿服志》 (Book of the Later Han)

「弓矢置於筒中。」

“Bows and arrows were kept inside a tube.”

筒 = bamboo tube; cylindrical case.

《宋書·符瑞志》 (Book of Song Dynasty)

「以竹為筒，達書於遠。」

“They made tubes of bamboo to send letters to distant places.”

筒 used for document tubes.

《本草綱目·器用部》 (Compendium of Materia Medica)

「藥筒可以藏丸。」

“A medicine tube can store pellets.”

筒 = cylindrical container.