/ Thesaurus / F Synonyms of fossilise Find synonyms for: Verb1. fossilize, fossilise, convertusage: convert to a fossil; "The little animals fossilized and are now embedded in the limestone"2. fossilize, fossilise, senesce, age, get on, mature, maturateusage: become mentally inflexibleWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: heifer Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language