fast

adjective /fæst/

Moving or operating at high speed.

Quick answer

Common synonyms for "fast" include quick, swift, rapid, speedy, fleet. Choose by context — see groups below.

Synonyms for "fast"

fast — quick in motion

quickswiftrapidspeedyfleet

fast — happening quickly

rapidspeedyexpeditedpromptimmediate

Antonyms for "fast"

slowsluggishleisurely

Examples in context

  • She's a fast reader — knocks out a novel a week.
  • We need a fast turnaround on this.
  • Markets move fast right now.
Usage note

For people: nimble, agile, quick-thinking. For processes: expedited, immediate, prompt.