The Collaborative International Dictionary
Tympanum \Tym"pa*num\, n.; pl. E. Tympanums, L. Tympana. [L., a kettledrum, a drum or wheel in machines, the triangular area in a pediment, the panel of a door, Gr. ?, ?, fr. ? to strike, beat. See Type, and cf. Timbrel.]
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(Anat.)
The ear drum, or middle ear. Sometimes applied incorrectly to the tympanic membrane. See Ear.
A chamber in the anterior part of the syrinx of birds.
(Zo["o]l.) One of the naked, inflatable air sacs on the neck of the prairie chicken and other species of grouse.
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(Arch.)
The recessed face of a pediment within the frame made by the upper and lower cornices, being usually a triangular space or table.
The space within an arch, and above a lintel or a subordinate arch, spanning the opening below the arch.
(Mech.) 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.
Wiktionary
Usage examples of "tympanums".
The two oak front doors stood under handsome limestone tympanums that together cradled a stained-glass rose window, all surrounded by a cinquefoil arch.