同 The 同 sound set Mostly read ドウ See 同 as a kanji → These jōyō kanji all use 同 as a sound hint — a clue to pronunciation, not meaning. 銅 ドウ copper 洞 ドウ den, cave, excavation 筒 トウ cylinder, pipe, tube 胴 ドウ trunk, torso, hull (ship) ← All sound sets