How is “flat out” used?

In All the President's Men (1976), one line is: “No, we were never told flat-out, "Don't talk."”

Which movie is “flat out” from?

The clip at the top of this page is from All the President's Men (1976).

in a definite and direct way; completely; as fast or as hard as possible

American · Heard in 5 movies

Oxford80% of films
in a definite and direct way; completely
It's flat-out spoiling him.
No, we were never told flat-out, "Don't talk."
Oxford20% of films
as fast or as hard as possible

Definitions from the Oxford Advanced Learner's Dictionary, 9th edition

No, we were never told flat-out, "Don't talk."

Said in 8 films · #1