According to the dictionary: outstanding, notable, superior. Seriously, though, take any reasonable definition. If you asked me a number I'd say 1% but yeah, you could say top 0.1%. I can't see how that gives any more precise information though, given that we don't have a practical, objective way of measuring programming skills.
> Because under my definition of the term, I would expect there to be very few engineers in Hungary that match that description.
Why? I'd expect any country with >10 million people, very high level of literacy, a couple of good universities and internet connectivity to be home to a good number of top-notch programmers. I can't see how that's particularly controversial.
In any case I'm not sure why you're taking issue with this. I never said that Hungary has proportionally as many top-notch programmers as in Silicon Valley. My point is simply: hiring people in Hungary is no more expensive than in California in terms of U$; if you have a company with 20 programmers in SF you could sure find 20 replacements in Hungary and save on payroll.