flat-out

American  

[flat-out] / ˈflætˈaʊt /

adjective

Informal.

1. moving or working at top speed or with maximum effort; all-out.

   a flat-out effort by all contestants.

2. downright; thoroughgoing.

   Many of the paintings were flat-out forgeries.

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flat out Idioms  

1. In a direct manner, bluntly. For example, He told the true story flat out . [ Colloquial ; mid-1900s]

2. At top speed, as in She was running flat out to catch the train . [ Slang ; c. 1930]

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Etymology

Origin of flat-out

First recorded in 1925–30

Example Sentences

But buyers with FHA loans sometimes face flat-out rejection, and some sellers state upfront that they won’t do business with FHA buyers.

From MarketWatch

The antithesis of laser-focused, but loved all the more for it, Hunt lived his whole life flat-out, dying after a heart attack at 45 in 1993, at the time working as a BBC F1 pundit.

From BBC

That is just flat-out impermissible under the law as it stood on Thursday.

From Slate

“Read them carefully. Otherwise your head just may explode at some point during this Los Angeles premiere, which presupposes an intimate familiarity with Czech history, the early rock scene and, oh, did we mention Sapphic poetry? It’s all a bit ostentatious and difficult to follow — but even at his most intellectually prolix, Stoppard is flat-out brilliant, arguably our greatest living playwright.”

From Los Angeles Times

Downing Street has flat-out denied that.

From BBC