rapid

rapid — adjective

1. happening very quickly or at a fast rate — for example, a rapid rise in prices,

1.adjectiveB1
Definition

happening very quickly or at a fast rate — for example, a rapid rise in prices, rapid growth of a city, or a rapid heartbeat after exercise.

Example

Tomás noticed a rapid change in the weather before the storm hit.

collocation: rapid change

The hospital’s rapid response saved the injured cyclist’s life.

collocation: rapid response

Common collocations
  • rapid growth
  • rapid change
  • rapid increase
  • rapid decline
  • rapid expansion
  • rapid response
  • rapid development
  • rapid rise
  • rapid progress
  • rapid pulse
Synonyms
  • fast

    most common and informal; used for movement of people, vehicles, or objects (fast car, fast runner)

  • quick

    emphasises short duration or promptness, often with actions (quick reply, quick decision)

  • swift

    slightly more formal than fast; suggests smooth, effortless movement (swift current, swift response)

  • speedy

    focuses on efficiency and lack of delay, often with processes (speedy delivery, speedy recovery)

Antonyms
  • slow

    the direct opposite in terms of speed or rate

  • gradual

    emphasises happening slowly over time, step by step, rather than all at once

Grammar Patterns

rapid + noun (change / growth / increase / response / expansion)

so + rapid + that-clause

Usage Note

Frequently used before nouns describing change, growth, or processes (rapid increase, rapid change, rapid growth). Less common in predicative position than fast or quick, and rarely used to describe human or animal movement (a rapid runner sounds unnatural; prefer fast).

Common Mistakes

He is a rapid runner.
He is a fast runner.
'rapid' is rarely used to describe a person’s running speed; 'fast' is the natural choice for human movement.
I made a rapid decision to buy the car.
I made a quick decision to buy the car.
'quick' emphasises short duration or promptness, while 'rapid' is better for ongoing processes.

rapid — noun

Word family

  • rapidly
    adverbB1
  • rapidity
    nounC1
  • rapidness
    nounC2

Synonym discussion

Sense: adjective/1

Fast is the most common and informal of the four, used for people, vehicles, and objects (a fast car, a fast runner). Quick emphasises short duration or promptness and suits single actions or responses (a quick reply, a quick look). Swift is slightly more formal and often suggests smooth, graceful, or effortless movement (a swift current, a swift recovery). Speedy focuses on efficiency and lack of delay, particularly with processes or services (speedy delivery, speedy processing). Rapid stands apart because it typically describes rates, processes, or changes rather than physical movement (rapid growth, rapid change). Use fast for a running person, quick for a brief glance, swift for a flowing river, speedy for a fast check-out, and rapid for a rising trend.

fast ↗quick ↗swift ↗speedy ↗

Common collocations

Nouns

  • rapid growth
  • rapid change
  • rapid increase
  • rapid expansion
  • rapid response
  • rapid decline
  • rapid progress
  • rapid development
  • rapid rise
  • rapid pulse

Adverbs

  • remarkably rapid
  • increasingly rapid
  • surprisingly rapid
  • relatively rapid

Phrases

  • in rapid succession
  • at a rapid rate
  • at a rapid pace

Prepositions

  • at a rapid pace
  • at a rapid rate
  • in rapid succession

Etymology

LatinFrenchEnglish

Rapid comes from the Latin word rapidus, meaning 'seizing, swift, or violent,' which in turn comes from rapere 'to seize or carry away.' The sense of 'very fast' developed from the idea of something being carried away with force. English borrowed it in the early 1600s from French rapide. The noun sense (rapids in a river, early 1800s) grew from the same root: a place where the current seems to 'seize' and carry boats or objects swiftly downstream.