/ Thesaurus / E Synonyms of eocene epoch Find synonyms for: Noun1. Eocene, Eocene epochusage: from 58 million to 40 million years ago; presence of modern mammalsWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language