In Spanish, "hundo" is the first person singular conjugation for the verb hundir - it has different meanings depending on the context of the sentence, but essentially it means "to sink, to bury, to devastate, or to destroy". So "hundo" would be "I sink", "I bury", and so on.
The Spanish translation for 100 is "cien" and $100 is "ciento dolares". And "3 for $100" would be "tres por ciento dolares" or "tres por cien" if you aren't being grammatically correct. I would assume that Portuguese, Italian, & French would all be similar to those translations - but I don't know any languages besides the romance ones, so I guess it could mean $100 in a language I'm not familiar with.
If I figure it out, I'll let you know. Either way, try not to stress over it -detach detach detach.