A juggernaut ( North-American pronunciation) in colloquial English usage is a literal or metaphorical force regarded as mercilessly destructive and unstoppable. Originating ca. 1850, the term is a metaphorical reference to the Hindu Ratha Yatra temple car, which apocryphally was reputed to crush devotees under its wheels.
The word is derived from the Sanskrit Jagannātha (Devanagari जगन्नाथ) "world-lord", one of the names of Krishna found in the Sanskrit epics.
The English loanword juggernaut in the sense of "a huge wagon bearing an image of a Hindu god" is from the 17th century, inspired by the Jagannath Temple in Puri, Orissa, which has the Ratha Yatra ("chariot procession"), an annual procession of chariots carrying the murtis (statues) of Jagannâth (Krishna), Subhadra and Balabhadra (Krishna's elder brother).
The first European description of this festival is found in the 14th-century The Travels of Sir John Mandeville, which apocryphally describes Hindus, as a religious sacrifice, casting themselves under the wheels of these huge chariots and being crushed to death. Others have suggested more prosaically that the deaths, if any, were accidental and caused by the press of the crowd and the general commotion.
The figurative sense of the English word, with the sense of "something that demands blind devotion or merciless sacrifice" was coined in the mid-19th century. For example, it was used to describe the out-of-control character Hyde in Robert Louis Stevenson's Dr. Jekyll and Mr. Hyde. The term is often applied to a large machine, or collectively to a team or group of people working together (such as a highly successful sports team or corporation), or even a growing political movement led by a charismatic leader—and it often bears an association with being crushingly destructive.