What is the meaning of Flat_out?

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

Complete, total, downright.

Very busy.

Lazy, sleeping.

At top speed.

Without hesitation or reservation, bluntly, no holds barred, totally, outright.

A total failure.

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

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

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

A uncambered corner of racetrack; a racetrack whose corners are uncambered.

To fail after a promising beginning; to disappoint expectations.

Synonym of flatten out (to make flat)

Source: wiktionary.org