Precambrian period

Từ điển WordNet v3.1 - WordNet Dictionary

noun

the eon following the Hadean time and preceding the Phanerozoic eon;
from about 3,800 million years ago until 544 million years ago
• Syn:
Precambrian, Precambrian eon, Precambrian aeon
• Instance Hypernyms:
eon, aeon
• Part Meronyms:
Proterozoic, Proterozoic eon, Proterozoic aeon, Archean, Archean eon,
Archean aeon, Archeozoic, Archaeozoic, Archeozoic eon, Archaeozoic aeon