The word "juggernaut" came up in a meeting at work recently, and some non-native English speakers hadn't heard it before.
There was some joking reference to the comic-book character (and some people thought this was the origin of the word). Someone explained that a juggernaut is an unstoppable force or object, to which I replied "I don't know about that. I think Wolverine could stop him..."
The real origin of the word is quite interesting: it comes from the Sanskrit word Jaganatha, as this Wikipedia page explains. (This list of English words of Sanskrit origin is also pretty interesting - e.g. candy, cash, ginger, jackal, jungle, lilac, loot, sugar)