前寒武紀 [－－－纪]

Jyutping cin4 hon4 mou5 gei2
Pinyin qián hán wǔ jì

Definitions (CC-CEDICT)
  1. pre-Cambrian, geological period before c. 540m years ago
Definitions (Wiktionary)
  1. name
    the Precambrian supereon (spanning from the formation of the Earth around 4.6 billion years ago to the emergence of hard-shelled creatures 541 million years ago)