"a small firework that consists of a percussion cap and some gravel wrapped in paper; explodes when thrown forcefully against a hard surface"
"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"
"armament consisting of a long cylindrical self-propelled underwater projectile that detonates on contact with a target"
"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"