from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. The most recent of the Martian geologic epochs, from approximately 1.8 billion (1800 million) years ago (the end of the Hesperian epoch) to the present.
Named for Amazonis Planitia. (Wiktionary)
Sorry, no example sentences found.
Wordnik is becoming a not-for-profit! Read our announcement here.