| Archean Period | ยุคอาร์เคียน [ธรณีวิทยา๑๔ ม.ค. ๒๕๔๖] |
| archean | (n) the time from 3, 800 million years to 2, 500 million years ago; earth's crust formed; unicellular organisms are earliest forms of life, Syn. Archeozoic, Archean eon, Archaeozoic aeon, Archeozoic eon, Archean aeon, Archaeozoic |
| archean | (adj) of or relating to the earliest known rocks formed during the Precambrian Eon, Syn. archaean |