2. a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States
3. an explosive device that is set off in an oil well (or a gas well) to start or to increase the flow of oil (or gas)
4. a small firework that consists of a percussion cap and some gravel wrapped in paper; explodes when thrown forcefully against a hard surface
5. a small explosive device that is placed on a railroad track and fires when a train runs over it; the sound of the explosion warns the engineer of danger ahead
6. armament consisting of a long cylindrical self-propelled underwater projectile that detonates on contact with a target
7. any sluggish bottom-dwelling ray of the order Torpediniformes having a rounded body and electric organs on each side of the head capable of emitting strong electric discharges