This one isn't actually new to me now, but it was a few months ago, and I think it's a neat example of unexpected cultural differences, so I'll include it.
"Lac" is an alternate spelling of "lakh," which in India is a unit consisting 100,000 of something, often 100,000 Indian rupees, an amount currently equal to about $2200 US. So house prices or salaries are sometimes specified as, for example, "Rs. 30 lakhs"--which is to say, 3 million rupees, currently about $70,000 US.
What I find most interesting about this is that in the US, we don't generally measure things in tens of hundred-thousand-units per se; we measure in millions instead. But I don't see any particularly good reason to have one of those units as a standard instead of the other; just a cultural difference (presumably rooted in history).
Oh, yes, and a "crore" is 100 lakhs; ten million of something.