Window ( poker )

1) Window card. (The front card of the five in a draw poker hand, when the cards are squared together such that only one can be seen. Also door card.)
2) The window position in a hand. "I can see what he's got in the window." Also door.
3) A, usually, glass-enclosed opening into the cage through which the cage person conducts transitions, and thus, by extension, the cage itself. "Did you make it to the window?" means "Did you escape from that game with any chips?"