Synonyms of adv flat_out

2 senses of flat out

Sense 1
bluffly, bluntly, brusquely, flat out, roundly -- (in a blunt direct manner; "he spoke bluntly"; "he stated his opinion flat-out"; "he was criticized roundly")

Sense 2
flat out, like blue murder -- (at top speed; "he ran flat out to catch the bus"; "he was off down the road like blue murder")