flat out

Adjective

• Complete, total, downright.
• Very busy.
• Lazy, sleeping.

Adverb

• At top speed.
• Bluntly, no holds barred, totally, outright.

Noun

• 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.

Verb

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