flack out

flack out

 and flake out
Sl. to collapse with exhaustion; to lie down because of exhaustion. All the hikers flacked out when they reached the campsite. After a few hours, the hikers all flaked out.
See also: flack, out
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

flack (out)

in. to collapse in exhaustion; to go to sleep. Betsy flacked out at nine every night.
See also: flack, out
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • be on (one's) last legs
  • end of one's rope, at the
  • at the end of (one's) rope
  • at the end of rope
  • take a lot out of
  • take a lot out of (one)
  • poop out
  • pooped out
  • flake down