/ Thesaurus / O Synonyms of optic chiasm Find synonyms for: Noun1. optic chiasma, optic chiasm, chiasma opticum, chiasma, chiasm, decussationusage: the crossing of the optic nerves from the two eyes at the base of the brainWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language