# superfast

/ˈsupɝˌfæst/ (US) · CEFR B1 · Adjective

Source: https://englishreference.com/word/superfast
Updated: 2026-10-13

## Definition

extremely quick or moving at a very high speed. You use this to describe things like internet connections or trains that are much faster than normal.

For teachers: operating, moving, or performing at an exceptionally high speed. Often used to describe technological capabilities or transportation systems.

## Examples

- The new superfast train reaches the city in twenty minutes.
- The government promised to provide superfast broadband to every household in the rural district by next year.
- The transition to superfast computing has enabled researchers to model complex climate patterns with a level of detail that was previously impossible to achieve.

## Synonyms

rapid, swift, speedy, high-speed

## Antonyms

slow, sluggish

## Usage notes

- Typically used as an attributive adjective before a noun.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.