洞 (dòng) — cave, hole; (adj) thorough, penetrating

entries → 洞

TSUMUGU · TOCFL B2 (est.) · 字

洞 character · TOCFL B2 (est.)

洞＝氵＋同

ㄉㄨㄥˋ · dòng

noun — cave, hole; (adj) thorough, penetrating

字源 FORM — what the parts do

氵義water

同聲tóng — gives the sounda cover over a single opening

ITtóng → dòng — initial and tone shift

Water (氵) and 同, which carries the sound — the original sense is a swift, rushing current (疾流). The current bores through, hollowing out a cave or hole (山洞、洞穴); and what bores clean through gives the sense of seeing through: thorough, penetrating — 洞察、洞悉. 同 tóng gives the sound.

故事 STORY — a scene to remember it by

急水（氵）日夜沖刷，把山壁掏穿——一個洞。

Rushing water (氵) wears at the rock day and night until it bores clean through — a cave.

字源記憶法

意 · Meanings

(本義)疾流— a swift current

→山洞、洞穴— cave, hole常用

⇒洞察、洞悉— to see through, perceive clearly常用

(本義) original meaning · → ⇒ each arrow = one more step of extension