juggernaut

In the early 14th century, Franciscan missionary Friar Odoric brought to Europe the story of an enormous carriage that carried an image of the Hindu god Vishnu (whose title was Jagannath, literally, "lord of the world") through the streets of India in religious processions. Odoric reported that some worshippers deliberately allowed themselves to be crushed beneath the vehicle's wheels as a sacrifice to Vishnu. That story was probably an exaggeration or misinterpretation of actual events, but it spread throughout Europe anyway. The tale caught the imagination of English listeners, and by the 19th century, they were using juggernaut to refer to any massive vehicle (such as a steam locomotive) or to any other enormous entity with powerful crushing capabilities.