Tympanum

Tympanum: In anatomy, the drum of the ear, the eardrum, the tympanic membrane. The tympanum resembles the head of a tiny drum. It separates the middle ear from the external ear.

Etymology: The Latin term "tympanum auris" was introduced by Albertus Magnus circa 1225. A tympanum was a drum or similar instrument, as a tambourine or timbrel; also, the stretched membrane of a drum, a drum-head.