Definitions
1.AdjectiveUsed other than figuratively or idiomatically: see flat, out.
2.AdjectiveComplete, total, downright.
3.AdjectiveVery busy.
4.AdjectiveLazy, sleeping."flat out (like a lizard in the sun) - doing absolutely nothing"
5.AdverbAt top speed."After 10 minutes of running flat out, he was out of breath."
6.AdverbWithout hesitation or reservation, bluntly, no holds barred, totally, outright."She thought it was best to tell him she didn't love him flat out.; He was flat out furious when his car was stolen."
7.NounA total failure.
8.NounA baked portion of flatbread; a baked item that is not meant to rise.
9.NounA wrap, an item of food consisting of various ingredients wrapped in a tortilla or pancake.
10.NounA section of piste that is relatively flat, causing or allowing skiers to slow down.
11.NounAn uncambered corner of racetrack; a racetrack whose corners are uncambered.
12.VerbTo fail after a promising beginning; to disappoint expectations.
13.VerbSynonym of flatten out (to make flat)