/pay'lee en sef"euh lon'/ ; esp. Brit. /pal'ee-/ , n. , pl. paleencephala /-leuh/ .
(no longer in technical use) the more primitive part of the brain in the evolutionary development of animals, including all parts except the cerebral cortex and its related structures.
Also, paleoencephalon . Cf. neencephalon .
[ 1915-20; ]