唇齒 [－齿]

Jyutping seon4 ci2
Pinyin chún chǐ

Definitions (CC-CEDICT)
  1. lit. lips and teeth (idiom); fig. close partners
  2. interdependent
Examples (粵典–words.hk)
  1. Cantonese
    战友唇齿相依，一旦割席就会全军覆没。
    戰友唇齒相依，一旦割蓆就會全軍覆沒。
    zin3 jau5 seon4 ci2 soeng1 ji1, jat1 daan6 got3 zek6 zau6 wui5 cyun4 gwan1 fuk1 mut6.
    • Comrades are close to one another. Once split, they will be all done.