| 齿 chǐ |
| tooth ; |
| 牙齿 yá chǐ |
| 齿轮 chǐ lún | |
Illustrating several teeth in a mouth, it is very vividly delineated in oracle bone inscriptions. In bronze inscriptions, the radical 止 was added to indicate the sound. Since a pony grows a tooth each year, 齿 can be the metaphor for ”age”. |