qǔ
Also rendered: Tooth decay (this site; the word is a disease and not a tooth, and the rendering says so) · A decayed tooth (the literal reading of 齒蠹, a tooth with something eating it; closer to the graph and less like a diagnosis)
Reviewed · 2026-10-05
At a glance
Tooth decay — 齲 qǔ — and 《說文》 gives the word as 𤘐, 齒蠹也，从牙禹聲, with 齲 as the 或體 written from 齒; 區禹切. The phonophore is 禹, a worm, and 桂馥 says why: 禹，蟲也，故文从禹 — the tooth has something in it. 段玉裁 quotes 《釋名》: 齲，朽也，蟲齧之缺朽也, and 《史記》, where the 倉公 has a minister with 齲齒. This chapter gives it one line and no discussion: 齒齲，刺手陽明。不已，刺其脉入齒中，立已 — the shortest prescription it writes, and the only one for a disease rather than for a network vessel. The teeth return twice more, both times as a sign: 上齒寒 alongside the blocked nose and the nosebleed, and 齒脣寒痛 at the very end, where the evil has been carried up to the upper teeth. The word occurs once and has not appeared in any chapter transcribed on this site before.
Passages where the term does real work, with the original, pinyin and English on the same line.
Every rendering below is a decision about which reader is being addressed. There is no neutral option.
| This site | tooth decay | 齲 is 《說文》's 齒蠹 — a tooth with a worm in it — and the modern word for what that turns out to be is decay; the rendering keeps the disease rather than the tooth, because the chapter treats it as something to be punctured away |
| Shuowen | a worm-eaten tooth · 齒蠹 | the dictionary's own definition, with 桂馥's note that 禹 is itself the graph for a worm; right about the graph, and wrong about the cause |
| Modern | dental caries | the clinical term, which is what the word has turned out to describe; exact, and it loses both the worm and the reason a needle was ever pointed at it |
Search the glossary
Reading path
Guided routes through the corpus, each built on a handful of chapters and their key terms.
See all reading paths