相依为命

相依為命
xiāngyīwéimìng
  1. mutually dependent for life (idiom); to rely upon one another for survival
  2. interdependent

CEDICT

Entry Composition

1 相依 xiāngyī to be interdependent
=2 为 wéi
  1. as (in the capacity of)
  2. to take sth as
  3. to act as
  4. to serve as
  5. to behave as
  6. to become
  7. to be
  8. to do
  9. by (in the passive voice)
=2 为 wéi variant of 为 wéi
3 命 mìng
  1. life
  2. fate
  3. order or command
  4. to assign a name, title etc