ˈtɪmpənəm n. (pl. tympanums or tympana) 1 Anat. a
the middle ear. b the
tympanic membrane. 2 Zool. the membrane
covering the
hearing organ on the
leg of an
insect. 3 Archit. a a
vertical triangular space forming the
centre of a
pediment. b a
similar space
over a
door between the
lintel and the arch; a
carving on
this space. 4 a drum-wheel etc.
for raising
water from a
stream. [L f. Gk tumpanon drum f. tupto strike]