An English horn.
English horn definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a double-reed woodwind instrument similar to the oboe but larger and a fifth lower in pitch
English horn definition by American Heritage Dictionary
A double-reed woodwind instrument similar to but larger than the oboe and pitched lower by a fifth.
Origin: Translation of French cor anglais, perhaps alteration of cor anglé, bent horn (from the curved crook to which the mouthpiece is attached) : cor, horn + anglé, bent.