flat out adverb
informal 1 chiefly US : in a very clear and direct way
▪ I told him flat out that I have no intention of marrying him. ▪ We asked for more time but they refused us flat out. 2 : at the fastest possible speed
▪ The car does 180 mph flat out. ▪ We've been working flat out. [=as hard as possible] ▪ He was running flat out. [=as fast as possible] 3 usually flat-out US, informal — used to make a statement more forceful ▪ This class is just flat-out confusing. ▪ The movie was flat-out lousy. ▪ She flat-out [=completely] missed the target.
▪ 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. ▪ We've been working flat out. [=as hard as possible] ▪ He was running flat out. [=as fast as possible]
