| 兄 | xiōng | elder brother |
| 弟 | dì | younger brother; junior male; I (modest word in letter) |
| 阋 | xì | to argue; to quarrel |
| 于 | yú | in; at; to; from; by; than; out of; surname Yu; to go; to take; sentence-final interrogative particlesurname Yu |
| 墙 | qiáng | wall; CL:面,堵 |
| 外 | wài | outside; in addition; foreign; external |
| 御 | yù | to defend; to resist; imperial; (classical) to drive (a chariot); to manage; to govern |
| 其 | qí | his; her; its; theirs; that; such; it (refers to sth preceding it) |
| 侮 | wǔ | to insult; to ridicule; to disgrace |
| 兄弟 | xiōng dì | older and younger brother; brothers; brotherly; fraternal; CL:个 |
| 外御其侮 | wài yù qí wǔ | internal disunity dissolves at the threat of an invasion from outside (idiom) |
