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• flat-out
  flat-out

  adjective

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

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

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

See Examples For:

flat-out flat out

As it turns out, I’m hardly the only person to have felt hoodwinked, bamboozled, and/or flat-out deceived by my smartphone’s forecasts in 2026.

From Slate ● Aug. 21, 2026

Given all that, it is flat-out wrong to say that AI adoption is stagnating, says Ethan Mollick, a Wharton professor who studies how companies adopt AI.

From The Wall Street Journal ● Jun. 7, 2026

Animal activists noted that CNMI's new guidelines fell short of the flat-out bans on fur seen in other fashion weeks, but nevertheless called it progress.

From Barron's ● May 15, 2026

In any case, the rate of hiring this year is a big improvement over last fall, when the economy was flat-out losing jobs.

From MarketWatch ● May 7, 2026

“Why don’t you tell Maya how you flat-out lied to us?”

From "The Hate U Give" by Angie Thomas

“This is flat out a lie,” responded Kalshi’s co-founder and operating chief, Luana Lopes Lara, less than a half-hour later.

From The Wall Street Journal ● Aug. 12, 2026

Another person with a nut allergy wrote in an online review that they were "flat out refused service" despite accepting the risk and that the restaurants rule on allergies is "not an acceptable one".

From BBC ● Apr. 15, 2026

In a subsequent statement in Parliament, Defence Minister Luke Pollard insisted the government was "not waiting" on the investment plan to announce further defence projects, but was "working flat out to" get the document published.

From BBC ● Apr. 15, 2026

“Everything that we’ve got running is going to be flat out for the rest of the year,” Fitterling said.

From The Wall Street Journal ● Apr. 5, 2026

Talking to the New York Times, he claimed flat out, “California has a chance, but I think Washington will win.”

From "The Boys in the Boat: Nine Americans and Their Epic Quest for Gold at the 1936 Berlin Olympics" by Daniel James Brown