► fast moving with a lot of speed: The car was going pretty fast when it went off the road. Burglars work fast.
► quickly quickly means the same as fast but sounds slightly more formal: I ran quickly down the stairs.
► rapidly/speedily/swiftly fast. Used especially in writing: The boat was drifting rapidly away from us. The fire department arrived speedily after the call.
► at high speed/at great speed very fast. Used about the movement of a vehicle or object: The car went around the corner at high speed.
► briskly in a way that shows you want to get somewhere quickly. Used about the way someone walks: He locked his door and walked briskly down the street.
► hastily in a way that is too fast, especially so that you make mistakes: Maura hastily got ready for work, forgetting her lunch as she left.