冥古宙

Mínggǔ Zhòu
  1. (geology) the Hadean eon (part of the Precambrian supereon, spanning from around 4.6 to 4 billion years ago)
  2. the Hadean eon (part of the Precambrian supereon, spanning from around 4.6 to 4 billion years ago)

Wiktionary

Entry Composition

=1 冥 míng old variant of 冥 míng
=1 冥 míng
  1. dark
  2. deep
  3. stupid
  4. the underworld
=1 冥 mián only used in 顛冥／颠冥
=1 冥 miàn only used in 冥眴
=2 古 Gǔ surname Gu
=2 古 gǔ
  1. ancient
  2. old
  3. paleo-
=2 古 gù
  1. (obsolete on its own in Standard Chinese) alternative form of 固 (gù)
  2. (obsolete on its own in Standard Chinese) alternative form of 故 (gù)
  3. alternative form of 固 (gù)
  4. alternative form of 故 (gù)
=2 古 kū
  1. (obsolete on its own in Standard Chinese) only used in 古成
  2. only used in 古成
3 宙 zhòu
  1. eternity
  2. (geology) eon