Is it Horn? Or French Horn?
 
The International Horn Society recommends that HORN be recognized as the correct name for our instrument in the English language.
[From the Minutes of the First General Meeting, June 15, 1971, Tallahassee, Florida USA]

Only in the US and England is our instrument called the French Horn. It was the signaling instrument of the hunt. In other languages it's called Corno (Italian), Horn  or Waldhorn (German), Cor (French), all words for Horn. No one really knows exactly why Americans and Brits call it French. It is supposed that the horn came across the English Channel from France and that the descriptor "French" stuck.



To make matters worse, jazz players routinely refer to their instruments as horns, whether they're trumpets, trombones, or even saxes.

To avoid confusion I adopt the James Bond method of referring to my instrument. When someone asks what I play, I say: "The horn. French horn."
 
"The horn is the soul of the orchestra."
Robert Schumann