tympanum

noun10

1. •
   A vertical recessed triangular space between the sides of a pediment, typically decorated.
2. •
   The recessed triangular space within an arch, and above a lintel or a subordinate arch, spanning the opening below the arch.

   • It was a black-and-white picture of a Romanesque doorway, with flanking saints and a lively Last Judgement in the tympanum […]. — 2004
3. •
   Any of various anatomic structures in various animals with analogy to a drum head.
4. •
   The eardrum (tympanic membrane, membrana tympanica).

   • When he came around, the star sound was gone. The ringing it left in his tympana was a great confusion. — 2020
5. •
   The main portion of the middle ear: the tympanic cavity (cavitas tympani).
6. •
   A thin tense membrane covering the hearing organ on the leg or body of some insects, sometimes adapted (as in cicadas) for producing sound.
7. •
   A membranous resonator in a sound-producing organ in frogs and toads.
8. •
   (in certain birds) The labyrinth at the bottom of the windpipe.
9. •
   A drum-shaped wheel with spirally curved partitions by which water is raised to the axis when the wheel revolves with the lower part of the circumference submerged; used for raising water, as for irrigation.
10. •
    (no longer used) A drum.