WordNet sense 1 (the main cavity of the ear; between the eardrum and the inner ear):

middle ear, tympanic cavity

WordNet sense 2 (the membrane in the ear that vibrates to sound):

eardrum, myringa, tympanic membrane

WordNet sense 3 (a large hemispherical brass or copper percussion instrument with a drumhead that can be tuned by adjusting the tension on it):

kettle, kettledrum, timpani, tympani