/tim"peuh neuhm/ , n. , pl. tympanums, tympana /-neuh/ .
1. Anat. , Zool.
a. See middle ear .
b. See tympanic membrane .
2. Archit.
a. the recessed, usually triangular space enclosed between the horizontal and sloping cornices of a pediment, often decorated with sculpture.
b. a similar space between an arch and the horizontal head of a door or window below.
3. Elect. the diaphragm of a telephone.
4. a drum or similar instrument.
5. the stretched membrane forming a drumhead.
[ 1610-20; týmpanon drum, akin to týptein to beat, strike ]