flat-out

1 of 2

adjective

ˈflat-ˌau̇t 

1

: being or going at maximum effort or speed

2

: out-and-out, downright

it was a flat-out lie

flat out

2 of 2

adverb

1

: in a blunt and direct manner : openly

called flat out for revolution

—Nat'l Review

2

: at top speed or peak performance

the car does 180 m.p.h. flat out

3

usually flat-out

ˈflat-ˌau̇t 

: absolutely, downright

—usually used as an intensive

is just flat-out confusing

Synonyms

Adjective

• utter
• sheer
• absolute
• unconditional
• outright
• complete
• pure
• simple
• total
• definite
• damned
• damn
• downright
• perfect
• very

Examples of flat-out in a Sentence

Adjective

regarded their son-in-law as a flat-out loser and let him know it

Adverb

I told him flat out that I have no intention of marrying him.

We asked for more time but they refused us flat out.

The car does 180 mph flat out.

Recent Examples on the Web

Adjective

Holland is a flat-out bad and not-so-thrilling thriller whose saving grace is a very dedicated, Stepford Wives–esque Kidman. —Jihane Bousfiha, Vulture, 2 July 2025

Visually, the film's re-creation of space travel is flat-out stunning. —EW.com, 30 June 2025

Adverb

So, the first and foremost thing is, flat out, straight up, is the big gap in features wasn’t lack for lack of trying — and that precedes Yelling to the Sky. —Dominic Patten, Deadline, 4 July 2025

Good to hear his minicamp is off to a hot start — the kid can flat out play ball. — Ryan Fowler (@_RyanFowler_) June 11, 2025 Expert NFL analysis on the best NFL Anytime Touchdown predictions for Week 12, including Brian Robinson Jr's chances of getting into the end zone. —Dan Perry, MSNBC Newsweek, 18 June 2025

Word History

First Known Use

Adjective

1906, in the meaning defined at sense 1

Adverb

1932, in the meaning defined at sense 1

Rhymes for flat-out

• about
• bailout
• blackout
• blowout
• breakout
• burnout
• buyout
• checkout
• closeout
• cutout
• devout
• dropout