忘懷洞

忘怀洞
wànghuáidòng

memory hole (figurative place to which lost or forgotten information is sent)

Wiktionary

Entry Composition

1 忘懷 wànghuái to forget
=2 洞 dòng
  1. cave
  2. hole
  3. zero (unambiguous spoken form when spelling out numbers)

classifier: 個
=2 洞 tóng used in 洪洞 Hóngtóng, a county in Shanxi