An overwhelming or unstoppable force: "With the newly empowered juggernaut of the Pentagon bureaucracy gaining momentum, the president was no longer in control" (James Carroll).
[Hindi jagannāth, title of Krishna, from Sanskrit jagannāthaḥ, lord of the world : jagat, moving, the world (from earlier present participle of jigāti, he goes; see gwā- in the Appendix of Indo-European roots) + nāthaḥ, lord (from nāthate, he helps, protects).]
Word History: For centuries, the Indian city of Puri has held an annual festival in honor of the god Krishna, worshiped under his Sanskrit title Jagannāthaḥ, "Lord of the World." In the middle of the rainy season, devotees transport highly adorned figures representing Krishna, his brother Baladeva, and his half-sister Subhadra from the temple where they usually reside to another temple some two and a half miles away. There, Krishna enjoys the new locale until his return a week or two later. Krishna and his siblings are transported in three chariots—massive towerlike structures about 45 feet high, mounted on many wheels, and lavishly decorated. Thousands of devotees pull the chariots with ropes and are cheered on by a crowd of over a million pilgrims. Worshipers try to obtain blessings by touching the ropes, and some have been crushed in the throng or have fallen under the wheels. Early Western observers in colonial India greatly exaggerated the number of these deaths, however, and sensationalized reports of the incidents led to the borrowing of Jagannāthaḥ into English as juggernaut, "an irresistible force that rolls unstoppably over its victims."
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.