show-down n.
1904, from poker players’ slang term for the act of laying down the hands face-up (1892); see show (v.) + down (adv).
Examples from the Web for show-down Historical Examples of show-down
But then, when it came to a show-down she might not be so magnanimous as she had appeared tonight.
Mr. and Mrs. Haldeman-Julius
It was a show-down and, bulldog fighter though he was, Jasper Swope weakened.
Dane Coolidge
I think we’ll be able to count on him later, when it comes to the show-down.
Robert Ames Bennet
He knows that matters must soon come to a show-down with the bunch.
Robert Ames Bennet
Look here, Tom, we might as well have a show-down right now.
Ralph Henry Barbour