1. Eoarchean - Adjective
2. Eoarchean - Proper noun
Eoarchean (not comparable)
(geology) Of a geologic era within the Archaean eon from about 4600 to 3600 million years ago; the first single-celled life began at this time.
Eoarchean
(geology) The era from 4,000 Ma to 3,600 Ma.