世交

shìjiāo
(long time) friend of the family

CEDICT

  1. longstanding friendship between two families; generations of family friendship
  2. old family friend; long-term friend of the family

Wiktionary

世代彼此有交誼往來。

重編國語辭典

Entry Composition

1 世 shì
  1. life
  2. age
  3. generation
  4. era
  5. world
  6. lifetime
  7. epoch
  8. descendant
  9. noble
2 交 jiāo
  1. to hand over; to deliver; to pay (money); to turn over
  2. to make friends
  3. (of lines) to intersect
  4. variant of 跤 jiāo