- a woodwind instrument having a slender conical, tubular body and a double-reed mouthpiece.
- (in an organ) a reed stop with a sound like that of an oboe.
- (a word formerly used in communications to represent the letter O.)
- a navigation system utilizing two radar ground stations that measure the distance to an aircraft and then radio the information to the aircraft.
- a woodwind instrument of the family that includes the bassoon and cor anglais, consisting of a conical tube fitted with a mouthpiece having a double reed. It has a penetrating nasal tone. Range: about two octaves plus a sixth upwards from B flat below middle C
- a person who plays this instrument in an orchestra
