Breadcrumb Home > Thesaurus > P Synonyms of phanerozoic Find synonyms for: Noun1. Phanerozoic, Phanerozoic eon, Phanerozoic aeonusage: the period from about 5,400 million years ago until the presentWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of phanerozoic (Dictionary) ✖ Related Content Daily Word Quiz: tautology Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language