戶樞不蠹 [户枢－－]

Jyutping wu6 syu1 bat1 dou3
Pinyin hù shū bù dù

Definitions (CC-CEDICT)
  1. lit. a door hinge never becomes worm-eaten
  2. constant activity prevents decay (idiom)
Definitions (Wiktionary)
  1. phrase, idiomatic
    A door hinge never gets plagued by worms; a rolling stone gathers no moss
Definitions (Kaifangcidian)
  1. （沒有對應漢語詞彙）