moving or working at top speed or with maximum effort; all-out.
a flat-out effort by all contestants.
downright; thoroughgoing.
Many of the paintings were flat-out forgeries.
In a direct manner, bluntly. For example, He told the true story flat out . [ Colloquial ; mid-1900s]
At top speed, as in She was running flat out to catch the train . [ Slang ; c. 1930]
First recorded in 1925–30
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Or its reply is flat-out wrong on an opinion query like, “What’s your favorite ice cream?”
From The Wall Street Journal ● May 21, 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
But Bill Sutherland, a biologist at the University of Cambridge, has found that some dogma in conservation is flat-out wrong when put to the test.
From Slate ● Apr. 28, 2026
Then I had to add, flat-out lying, “It was Guzzo’s idea.”
From "All American Boys" by Jason Reynolds
The track's most iconic corner, the flat-out swerves known as Eau Rouge, has been easily flat out on a qualifying lap for the best part of two decades.
From BBC ● Jul. 18, 2026
So we'll go flat out and let's see how it goes.
From BBC ● Apr. 30, 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
Jacobson says they have computers now working flat out generating brackets for this year’s competition.
From MarketWatch ● Mar. 18, 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
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
