tympanum

plural tympanums · plural tympana

1. archaicA drum.
2. Any of various anatomic structures in various animals with analogy to a drum head:
   1. anatomyThe 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 [1992], Vernor Vinge, chapter 2, in A Fire Upon the Deep, 1st edition, New York: Tor Essentials, →ISBN, page 33

   2. anatomyThe main portion of the middle ear: the tympanic cavity (cavitas tympani).
   3. anatomyA thin tense membrane covering the hearing organ on the leg or body of some insects, sometimes adapted (as in cicadas) for producing sound.
   4. anatomyA membranous resonator in a sound-producing organ in frogs and toads.
   5. anatomy(in certain birds) The labyrinth at the bottom of the windpipe.
3. architectureA vertical recessed triangular space between the sides of a pediment, typically decorated.
   1. architectureThe 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, Alan Hollinghurst, The Line of Beauty […], London: Picador, →ISBN

4. engineeringA 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.