from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. 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.
- n. The Eoarchean era.
Sorry, no etymologies found.
Though commonly used, the Hadean is not a formal eon and no lower bound for the Eoarchean has been agreed upon.