- Any surface that vibrates in response to sound or is vibrated to emit sound, such as in microphones and loudspeakers. Also applied to wall and floor surfaces vibrating in response to sound or in transmitting sound.
- muscle that separates the thoracic and abdominal cavities
Source: Noland, George B. 1983. General Biology, 11th Edition. St. Louis, MO. C. V. Mosby