/ Thesaurus / G Synonyms of genus castoroides Find synonyms for: Noun1. Castoroides, genus Castoroides, mammal genususage: extinct beavers of the Pleistocene; of eastern and southern United StatesWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: placate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language