(tr, adverb) slang to abandon or leave (an attempt or enterprise)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
How to use jack in in a sentence
The jack-in-the-box has popped, just as we expected it to, but it still made us gasp.
But he couldn't see Uncle Wiggily because he was safely hidden in the Jack-in-the-pulpit.
So that's how the Jack-in-the-pulpit saved the rabbit and very thankful Uncle Wiggily was.
So the rabbit traveler looked up, and there he saw a flower called Jack-in-the-pulpit looking down on him.
Twant Absurdam, I'm moest sho, und hit twant Jack-in-de-bed, nudder.The Broken Sword | Dennison Worthington
A little drawer shoots out almost in my face, startling me like a jack-in-the-box.