Go to sleep, as in I racked out about midnight. This slangy expression, as well as the related rack time, for sleeping or snooze time, use rack to refer to being laid out on a framework, here a bed.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
How to use rack out in a sentence
He air a layin' up on th' road yonder now—I got t' rack out an' git yo' away from heah now.The Red Debt | Everett MacDonald
Oh, my dear, I will never let you sit upon the rack out of sight again unless you are tied fast to the seat!The Adventurous Seven | Bessie Marchant
Dawvys, a plump fellow with no hint of his enormous endurance in his look, motioned rack out of the library.The Buttoned Sky | Geoff St. Reynard
Then lift the rack out, pour the syrup into the kettle and cook to two hundred and twenty degrees.Candy-Making Revolutionized | Mary Elizabeth Hall
That fellow who pulled rack out of the drink saved me from getting a soaking, as I was just going overboard after Herb.Rival Pitchers of Oakdale | Morgan Scott