tympanum

(noun) the main cavity of the ear; between the eardrum and the inner ear. Synonyms: middle ear, tympanic cavity.

(noun) the membrane in the ear that vibrates to sound. Synonyms: eardrum, tympanic membrane, myringa.

(noun) a large hemispherical brass or copper percussion instrument with a drumhead that can be tuned by adjusting the tension on it. Synonyms: kettle, kettledrum, tympani, timpani.