informal to collapse or fall asleep as through extreme exhaustion
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
Other Idioms and Phrases with flake out
Drop from exhaustion, faint. For example, After running the marathon, be simply flaked out on the ground. This expression possibly is derived from a now obsolete meaning of flake, “to become flabby or fall in folds.” [Slang; c. 1940]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.