Idiom
flat out
Meanings
As fast as possible; at full speed.
With maximum effort; working extremely hard without a break.
Directly and completely; without qualification (often in statements or refusals).
Definition
With maximum effort or speed, without holding back.
“Flat out” is used to say someone is doing something as fast or as hard as possible. It often describes working, running, or driving at full speed. It can also mean saying something in a very direct, absolute way, leaving no doubt.
Examples
- We’ve been working flat out to finish the project on time.
- The driver went flat out on the straight stretch of road.
- She told him flat out that she wasn’t interested.
- I ran flat out but still missed the bus.
- They’re flat out preparing for the product launch.
Common mistake
Learners sometimes use “flat out” to mean “completely wrong” or confuse it with “flat-out” as an adjective, but the idiom is most often used adverbially for maximum effort/speed or directness.