tympanum

(archaic) A drum.

(anatomy, zootomy) The eardrum (tympanic membrane, membrana tympanica).

(anatomy, zootomy) The main portion of the middle ear: the tympanic cavity (cavitas tympani).

(zootomy, entomology) A thin tense membrane covering the hearing organ on the leg or body of some insects, sometimes adapted (as in cicadas) for producing sound.

(zootomy) A membranous resonator in a sound-producing organ in frogs and toads.

(zootomy) (in certain birds) The labyrinth at the bottom of the windpipe.

(architecture) A vertical recessed triangular space between the sides of a pediment, typically decorated

The recessed triangular space within an arch, and above a lintel or a subordinate arch, spanning the opening below the arch

(engineering) 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.