double reed

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A pair of joined reeds that vibrate together to produce sound in certain wind instruments, such as bassoons and oboes.
• noun An instrument in which sound is produced by a pair of joined reeds.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun music A pair of reeds, in any of several wind instruments, that are joined together and vibrate together

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a woodwind that has a pair of joined reeds that vibrate together
• noun a pair of joined reeds that vibrate together to produce the sound in some woodwinds