Expected Value
A term for math enthusiasts! It indicates how much profit (or loss) you can expect in the long term if you were to play a game a thousand times. Do you need to understand it? No. Should you? Perhaps. Can you appear knowledgeable with it? Definitely.
If you throw around phrases like “My EV on this hand was negative” during your next night at the casino, you're either a pro — or you just sound damn clever.