Wiktionary
flake out
vb. 1 (context intransitive English) To fall asleep from exhaustion. 2 (context intransitive English) To flake: to prove unreliable; to abandon or deseret.
WordNet
flake out
v. change from a waking to a sleeping state; "he always falls asleep during lectures" [syn: fall asleep, dope off, drift off, nod off, drop off, doze off, drowse off] [ant: wake up]
Usage examples of "flake out".
If it was starting to flake out on them now, they were in big trouble.
Bloody little organism trying to flake out and forget its problems.
What do you do, just set the carrier to run its fucking self and then flake out in it?