樞紐

枢纽
shūniǔ
  1. hub (e.g. of traffic network)
  2. hinge
  3. pivot
  4. fulcrum

CEDICT

Entry Composition

1 樞 shū (bound form) hinge; pivot (usu. fig.)
2 紐 niǔ
  1. to turn
  2. to wrench
  3. button
  4. nu (Greek letter Νν)