What is a torpedo?

According to the Merriam-Webster Dictionary, a torpedo is “a weapon for destroying ships by rupturing their hulls below the waterline: such as a submarine mine or a thin cylindrical self-propelled underwater projectile.”

In 1864, when Admiral Farragut said something along the lines of “Damn the torpedoes, Captain Drayton, go ahead” he was referring to what we think of as a minefield. In those days, a torpedo referred to any underwater weapon. However, in 1866 Robert Whitehead developed a motorized torpedo. This was the prototype of what we think of as a torpedo today, the last part of the definition above. What Admiral Farragut was concerned about is what we today call mines. We now just call the motorized torpedo a torpedo.