archean_eon | ||
1. | [ noun ] (geology) the time from 1.5 billion to 5 billion years ago; earth's crust formed; unicellular organisms are earliest forms of life | |
Synonyms: | Archaeozoic Archeozoic_era Archaeozoic_era archaeozoic_aeon archean archean_aeon archeozoic_eon Archeozoic | |
Related terms: | eon era Precambrian | |
Similar spelling: |
archean_aeon archean_era archaean archenteron archiannelid Archiannelida |