throw (one's) hand in

To give up on some endeavor; to quit or abandon something; to admit defeat or failure. An allusion to a card game, especially poker. I've been working on this book for over a year, and I'm getting nowhere with it. I think I'm ready to throw my hand in. After trying their hand in the smartphone market for just a few years, the company is already throwing their hand in after finding very little success.

throw your hand in

give up; withdraw from a contest.

In card games, especially poker, if you throw your hand in you retire from the game.

throw your ˈhand in

(informal) stop doing something or taking part in something, especially because you are not successful: If I fail again this time, I shall throw my hand in.

When you have no chance of winning in a game of cards, you throw your hand (= cards) into the middle of the table.