Fast and Flat-out

Fast adverb - With great speed.

Flat-out and fast are semantically related. in speedily topic. In some cases you can use "Flat-out" instead an adverb "Fast".

Nearby Words: fasted, fasting

Flat-out adjective - Having no exceptions or restrictions.

Fast and flat-out are semantically related. Sometimes you can use "Fast" instead an adverb phrase "Flat-out".