flat-out
adjective
Definitions
Complete, total, downright.
Very busy.
Lazy, sleeping.
Example: flat out (like a lizard in the sun) - doing absolutely nothing
adverb
Definitions
At top speed.
Example: After 10 minutes of running flat out, he was out of breath.
Bluntly, no holds barred, totally, outright.
Example: He was flat out furious when his car was stolen.