English definition of “flat”
/flæt/ adverb (flatter, flattest)
› in a horizontal or level position on a surface: She spread the cloth flat across the kitchen table.
flat out › using all your energy or effort: We've all been working flat out to finish the project on time.
in 5 minutes/30 seconds, etc flat › in exactly and only 5 minutes, 30 seconds, etc: He showered and got dressed in 10 minutes flat.