bellows

Concise Oxford English Dictionary © 2008 Oxford University Press:
bellows/ˈbeləʊz/

▶plural noun

• 1 a device with an air bag that emits a stream of air when squeezed together with two handles, used for blowing air into a fire.

  ■ a similar device used in a harmonium or small organ.

• 2 an object or device with concertinaed sides to allow it to expand and contract, such as a tube joining a lens to a camera body.

– origin ME: prob. from OE belga, pl. of belig (see belly).