timpanum

from The Century Dictionary.

• noun See tympanum.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun anatomy The eardrum.
• noun anatomy The middle ear.
• noun by extension The diaphragm of a telephone.
• noun zoology An external hearing organ in some insects.
• noun architecture An ornamental panel in any triangular space.
• noun music A kettledrum.