Definition of tympans:
(n) :
(music) The stretched membrane of a drum.
(n) :
(music) A percussion instrument consisting of a hollow cylinder with such a membrane at each end.
(n) :
The tympanum of the ear.
(n) :
(architecture) A tympanum.
(n) :
(printing) A piece of cloth padding placed under the platen of a letterpress to distribute the pressure on the sheet being printed.