I'm interested in finding some words where the US meaning is generally not understood outside the US.
One example is "biscuit". English speakers generally understand what "cookies" and "crackers" are, and they use "biscuits" to refer to them comprehensively, but I suspect that unless they've visited the US, they don't know that in the US a "biscuit" is a baked good served with the main mean, and very much like what they would call a "scone" (though there are "scones" in the US too).
Another is "entree", which if used outside the US means an appetiser or first course: not the main course, as it does in the US.
Any other good examples? (And not words like "automobile" or "elevator", which are not used but which are still understood outside the US).