脳のう弓きゅうMeanings1nounfornix (of the brain); fornix cerebriAnatomical term for the C-shaped bundle of nerve fibers in the brain, part of the limbic system.脳のう弓きゅうは記き憶おくや感かん情じょうに関かかわる神しん経けい線せん維いの束たばです。The fornix is a bundle of nerve fibers involved in memory and emotion.