Definition from Wiktionary, the free dictionary
109 (plural 109s)
- (dated, informal, military, World War II) The German Messerschmitt 109 fighter aircraft.
1998, Middle Tenessee WWII Fighter Pilots Association, Missions Remembered: Recollections of the World War II Air War, page 68:
- Four 109s were spotted and attacked. After a dogfight, all four had been shot down. Three crashed on the same field.