Archean - Definition
archean
adj 1: of or relating to the earliest known rocks formed during
the Precambrian Eon [syn: archean, archaean]
n 1: 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: Archean, Archean eon,
Archean aeon, Archeozoic, Archaeozoic, Archeozoic
eon, Archaeozoic aeon]