ETYM Latin, a kettledrum, a drum or wheel in machines, the triangular area in a pediment, the panel of a door.
(Irregular plural: tympanums, or: tympana).
1. The ear drum, or middle ear. Sometimes applied incorrectly to the tympanic membrane.
2. A chamber in the anterior part of the syrinx of birds.
3. The recessed face of a pediment within the frame made by the upper and lower cornices, being usually a triangular space or table.
4. The space within an arch, and above a lintel or a subordinate arch, spanning the opening below the arch.
5. 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.
Space within an arch; arched recess at entrance of cathedral.
Ear-drum; Archtitecture, triangular face of pediment; space within arch.