Tympanum - Definition

n 1: the main cavity of the ear; between the eardrum and the
inner ear [syn: middle ear, tympanic cavity,
tympanum]
2: the membrane in the ear that vibrates to sound [syn:
eardrum, tympanum, tympanic membrane, myringa]
3: a large hemispherical brass or copper percussion instrument
with a drumhead that can be tuned by adjusting the tension on
it [syn: kettle, kettledrum, tympanum, tympani,
timpani]