Simple Definition of flat out
: in a very clear and direct way
: at the fastest possible speed
—used to make a statement more forceful
Examples of flat out
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.
First Known Use of flat out
FLAT OUT Defined for Kids
Definition of flat out
1 : in a very clear manner <I told him flat out to leave.>
2 : at top speed <We worked flat out to finish.>
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