元古宙

Yuángǔ Zhòu
  1. (geology) the Proterozoic eon (part of the Precambrian supereon, spanning from 2.5 billion to 541 million years ago)
  2. the Proterozoic eon (part of the Precambrian supereon, spanning from 2.5 billion to 541 million years ago)

Wiktionary

Homographs

元古宙 Yuángǔzhòu pre-Cambrian (geological eon 2500-645m)

Entry Composition

1 元古 yuángǔ primeval past
2 宙 zhòu
  1. eternity
  2. (geology) eon