epithalamus

noun
epi·​thal·​a·​mus | \ ˌep-ə-ˈthal-ə-məs How to pronounce epithalamus (audio) \
plural epithalami\ -​ˌmī How to pronounce epithalami (audio) \

Medical Definition of epithalamus

: a dorsal segment of the diencephalon containing the habenula and the pineal gland