Question about a scene from the movie CASINO!!!?

Question

Hello all! I love the movie "Casino" with DeNiro & Pesci, but there's one scene that I just don't follow with regards to "casino lingo":

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INT. ACE'S BEDROOM - NIGHT

ACE (Into telephone): What is it?

SHERBERT (Over telephone): The little guy. He's half in the bag, and nobody told him he was eighty-sixed from the joint, so we all turned our heads and made out like we didn't know who he was. He's over at the twenty-one table with his nose wide open. He took the money out of his own kick. His nose is open for about ten thousand. Now, he's really pissed!

ACE: Oh, no.

SHERBERT: He wants a fifty-thousand marker.

ACE: No, just - just give him, give him ten. That's it. Ten. I'll be right down.
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Ok, so... twenty-one table = Blackjack table. That I understand. But whats the whole "marker" thing about?

Answer 1

A marker is essentially an IOU used by a player to borrow money from a casino.