/ Thesaurus / P Synonyms of pachycephalosaurus Find synonyms for: Noun1. pachycephalosaur, pachycephalosaurus, bone-headed dinosaurusage: bipedal herbivore having 10 inches of bone atop its head; largest boneheaded dinosaur ever foundWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language