Definition of "trey"

Before you begin the Game at Picket, you must throw out of the Pack the Deuces, Treys, Fours and Fives, and play with the rest of the Cards, which are in number thirty and six.

1674, Charles Cotton, chapter 6, in The Compleat Gamester‎, London: R. Cutler, page 81

He had been a pretty good guy, straight as ace-deuce-trey-four-five, till he got on the force.

1929, Dashiell Hammett, chapter 11, in Red Harvest‎

You see, Sir, when I look at the Ace it reminds me that there is but one God. The deuce reminds me that the bible is divided into two parts; the Old and New Testaments. And when I see the trey I think of the Father, Son and Holy Ghost.

1948 January 1, “Deck of Cards” (track 20), in Famous Country Music Makers‎, performed by Tex Ritter

Davidson had caught a trey which did not seem to improve his hand, yet he threw three dollars into the pot.

1982, Stephen King, The Man Who Would Not Shake Hands