唇齒相依 chún chǐ xiāng yī

DEFINITIONS

  1. lit. as close as lips and teeth (idiom); closely related
  2. interdependent

CHARACTERS

唇 chún lips
齒 chǐ teeth; gears, cogs; age; KangXi radical 211
相 xiāng mutual, reciprocal, each other
依 yī rely on, be set in; consent, obey a wish