Pronunciation: (shō'doun"), [key]
1. the laying down of one's cards, face upward, in a card game, esp. poker.
2. a conclusive settlement of an issue, difference, etc., in which all resources, power, or the like, are used; decisive confrontation: An international showdown was inevitable.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.