Definition of "flat out" in English

Adjective

1. Used other than figuratively or idiomatically: see flat,‎ out.

2. Complete, total, downright.

3. Very busy.

4. Lazy, sleeping.

   • flat out (like a lizard in the sun) - doing absolutely nothing

Adverb

1. At top speed.

   • After 10 minutes of running flat out, he was out of breath.

2. Without 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.

Noun

1. A total failure.

2. A baked portion of flatbread; a baked item that is not meant to rise.

3. A wrap, an item of food consisting of various ingredients wrapped in a tortilla or pancake.

4. A section of piste that is relatively flat, causing or allowing skiers to slow down.

5. An uncambered corner of racetrack; a racetrack whose corners are uncambered.

Verb

1. To fail after a promising beginning; to disappoint expectations.

2. Synonym of flatten out (to make flat)