tympanum

noun (plural tympanums or tympana /-nə/)

• 1 Anatomy & Zoology the tympanic membrane or eardrum.
• Entomology a membrane covering the hearing organ on the leg or body of some insects, sometimes adapted (as in cicadas) for producing sound.

• 2 Architecture a vertical recessed triangular space forming the centre of a pediment, typically decorated.
• a recessed triangular space over a door between the lintel and the arch.

• 3 archaic a drum.