The ear drum, or middle ear. Sometimes applied incorrectly to the tympanic membrane. See Ear.
- Anatomy See middle ear.
- See eardrum.
- Zoology A membranous external auditory structure, as in certain insects.
- Architecture The ornamental recessed space or panel enclosed by the cornices of a triangular pediment.
- Architecture A similar space between an arch and the lintel of a portal or window.
- The diaphragm of a telephone.