/ Thesaurus / T Synonyms of thalmencephalon Find synonyms for: Noun1. diencephalon, interbrain, betweenbrain, thalmencephalon, neural structureusage: the posterior division of the forebrain; connects the cerebral hemispheres with the mesencephalonWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: ravenous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language