n.1 esp. Brit. a large heavy motor vehicle, esp. an articulated lorry.
2 a huge or overwhelming force or object.
3 (Juggernaut) an institution or notion to which persons blindly sacrifice themselves or others.
Etymology: Hindi Jagannath f. Skr. Jagannatha lord of the world: name of an idol of Krishna in Hindu mythol., carried in procession on a huge cart under which devotees are said to have formerly thrown themselves