Home / Synonyms / fast

Another word for fast

Fast (adjective, adverb, noun, verb): Moving or happening quickly; also used for food abstinence and to describe firm attachment or a period of abstaining from food. Below are 24 synonyms across 4 senses. Tap a chip for its nuance and an example.

Most formal: fleet, expeditiously, staunchStrongest: starve, immovable, rapid

Writing for

24 synonyms shown

Chip depth = intensity (mild → extreme) dots = formality (slang → academic)

Quick movement · adjective

moving or able to move at high speed

Very quickly · adverb

at high speed; without delay

Abstain from food · verb

to go without food for a period, usually for religious or health reasons

Firm attachment · adjective

fixed firmly or securely; difficult to move

Find the right strength and register

Drag the amber target to how strong and how formal you need the word to be. The three closest synonyms light up.

quickrapidspeedyswiftbriskhastyfleet
milderintensity →stronger
formal ↑

You asked for: equal strength, neutral register

  1. quick — more general and less forceful
  2. rapid — more formal, emphasizes speed of process
  3. speedy — friendly, informal emphasis on speed

The dashed ring marks “fast” itself: neutral strength, neutral register.

Synonyms for fast in your sentence

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How to choose

Choose the plainest synonym when you just mean speed, and reserve more formal words like rapid, swiftly, or expeditiously for reports and polished prose. For the food sense, fast is the standard verb; avoid speed-related synonyms, which do not fit that meaning.

Antonyms of fast

All synonyms at a glance

SynonymStrengthFormalityBest for
quick2/5neutralcasual, business, academic
rapid3/5formalbusiness, academic
speedy3/5casualcasual, business
swift3/5formalacademic, business, creative
brisk2/5neutralbusiness, casual
hasty2/5neutralacademic, business, casual
fleet3/5academiccreative, academic
quickly2/5neutralcasual, business, academic
rapidly3/5formalacademic, business
swiftly3/5formalbusiness, academic, creative
promptly2/5formalbusiness, academic
speedily3/5neutralbusiness, academic, casual
expeditiously3/5academicbusiness, academic
abstain3/5formalacademic, business, casual
go without food3/5neutralcasual, academic
starve5/5neutralcasual, creative
diet2/5neutralcasual, business
fasting3/5formalacademic, business, casual
firm2/5neutralcasual, business, academic
secure3/5neutralbusiness, academic, casual
tight2/5casualcasual, business
stable3/5formalacademic, business
immovable4/5formalacademic, creative, business
staunch3/5academiccreative, academic

Questions about synonyms for fast

What is the most formal or academic synonym for fast?

It depends on the sense. For speed, rapid and expeditiously are among the most formal choices; for firm attachment, stable or immovable can sound more formal than fast.

What is a stronger or milder alternative to fast?

A milder alternative is quick or brisk, which sounds less forceful. A stronger alternative is rapid or swift, which emphasizes speed more strongly or more elegantly.

Is fast usually better than quickly?

Fast is usually the adjective or adverb of choice in everyday speech, especially in phrases like a fast car or move fast. Quickly is more neutral as an adverb and often sounds a bit more formal in writing.

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