A rate that is rapid.

synonyms: quickness, rapidity, rapidness, speediness.

Roget 274: velocity, speed, celerity; swiftness etc. adj.; rapidity, eagle speed; expedition etc. (activity) 682; pernicity^†; acceleration; haste etc. 684.    spurt, rush, dash, race, steeple chase; smart rate, lively rate, swift rate etc. adj.; rattling rate, spanking rate, strapping rate, smart pace, lively pace, swift pace, rattling pace, spanking pace, strapping pace; round pace; flying, flight.    lightning, greased lightning, light, electricity, wind; cannon ball, rocket, arrow, dart, hydrargyrum [Lat.], quicksilver; telegraph, express train; torrent.    eagle, antelope, courser, race horse, gazelle, greyhound, hare, doe, squirrel, camel bird, chickaree^†, chipmunk, hackee [U.S.], ostrich, scorcher [Slang].    Mercury, Ariel^†, Camilla^†, Harlequin.    [Measurement of velocity] log, log line; speedometer, odometer, tachometer, strobe, radar speed detector, radar trap, air speed gauge, wind sock, wind speed meter; pedometer.    ... show more

Dutch: snelheid
Polish: wartkość, płynność, potoczystość