/ Thesaurus / C Synonyms of cretaceous period Find synonyms for: Noun1. Cretaceous, Cretaceous periodusage: from 135 million to 63 million years ago; end of the age of reptiles; appearance of modern insects and flowering plantsWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: quandary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language