hypotympanum

noun
hy·​po·​tym·​pa·​num | \ -ˈtim-pə-nəm How to pronounce hypotympanum (audio) \
plural hypotympana\ -​nə How to pronounce hypotympana (audio) \ also hypotympanums

Medical Definition of hypotympanum

: the lower part of the middle ear — compare epitympanum