Definition of "tympanum" [tym•pa•num]

• Anatomy See middle ear. (noun)
• See eardrum. (noun)
• Zoology A membranous external auditory structure, as in certain insects. (noun)
• Architecture The ornamental recessed space or panel enclosed by the cornices of a triangular pediment. (noun)
• Architecture A similar space between an arch and the lintel of a portal or window. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The border of the tympanum is very charming; the children quite beautifully painted."
• "Fourthly, there are two nerves within the ears, so attached to three small bones that are mutually sustaining, and the first of which rests on the small membrane that covers the cavity we call the tympanum of the ear, that all the diverse vibrations which the surrounding air communicates to this membrane are transmitted to the mind by these nerves, and these vibrations give rise, according to their diversity, to the sensations of the different sounds."
• "On the other side of the tympanum is a small air-filled space called the tympanic cavity."