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The number of cigarettes that you are willing to part with out of the package you bought with the hope that someone will return the favour when you need one.
Can I bum a smoke?

Yes but I only have one left.

But I see that you have half a pack!

Yes, but this is the last one of my karma smokes.

It's ok, when you run out I'll give you one.
by nathrasha December 06, 2008