戶樞不蠹 hù shū bù dù

DEFINITIONS

  1. lit. a door hinge never becomes worm-eaten
  2. constant activity prevents decay (idiom)

CHARACTERS

戶 hù door; family, household
樞 shū door hinge; pivot; center of power
不 bù
HSK 1
no, not; un-; negative prefix
蠹 dù moth; insects which eat into clot