Lewis Short
tympănum | typă-num (noun N) = τύμπανον: (collat. form , Cat. 63, 8 sq.)
* A drum, timbrel, tambour, tambourine.
* Lit.
* Esp., as beaten by the priests of Cybele, Lucr. 2, 618; Cat. 63, 8 sq.; Verg. A. 9, 619; Ov. M. 3, 537; 4, 29; 4, 391; id. F. 4, 213; Plaut. Poen. 5, 5, 38; Caes. B. C. 3, 105; Curt. 8, 11, 20; 8, 14, 10; Tac. H. 5, 5, —Also by the Bacchantine females, Ov. M. 11, 17.—Beaten by the Parthians as a signal in battle in place of the tuba, Just. 41, 2, 8.
* Transf., of things of a like shape.
* A drum or wheel, in machines for raising weights, in water-organs, etc., Lucr. 4, 905; Verg. G. 2, 444; Vitr. 10, 4; Plin. 18, 34, 77, § 332; Dig. 19, 2, 19.
* In archit.
* The triangular area of a pediment, Vitr. 3, 3 med.
* A panel of a door, Vitr. 4, 6 med.
* A part of the clepsydra, called also phellos, Vitr. 9, 9.
Charlton T. Lewis, Charles Short, A Latin Dictionary