high speed

high speed — noun

IPA/hˈaɪ spˈiːd/
IPA/hˈaɪ spˈiːd/

1. the condition in which something moves, travels, or happens at a rate that is mu

1.nounB1
Definition

the condition in which something moves, travels, or happens at a rate that is much faster than what is usual or normal

Example

The express train travels at high speed from Paris to Lyon in under two hours.

pattern: at high speed

Data can be transferred at high speed through the new fibre-optic network.

Common collocations
  • at high speed
  • reach a high speed
  • maintain a high speed
  • travel at high speed
Synonyms
  • fast rate

    more general; works for any process, not just motion

  • rapid pace

    slightly more formal; often used for change or development, not physical movement

Antonyms
  • low speed

    the direct opposite in terms of rate of motion

Grammar Patterns

at + high speed

Usage Note

Usually follows the preposition 'at' when describing motion (at high speed). The noun 'speed' can also be modified by other adjectives (low speed, top speed) but 'high speed' is the most common pairing.

Common Mistakes

The train moves in high speed.
The train moves at high speed.
The correct preposition is 'at', not 'in'.
The car increased its high speed.
The car reached a high speed.' or 'The car increased its speed.
'High speed' typically follows 'at' or 'reach', not 'increase'.

high speed — adjective

IPA/ˌhaɪˈspiːd/
IPA/ˌhaɪˈspiːd/

Word family

Synonym discussion

Sense: adjective/1

All four words describe something that moves or happens quickly, but they differ in usage. 'Fast' is the most general and common word — it can describe vehicles, processes, or people, and works both before a noun ('a fast car') and after a linking verb ('the car is fast'). 'Rapid' is slightly more formal and often describes change, growth, or development ('rapid economic growth') rather than physical motion. 'Express' is limited to transport and delivery services ('express train', 'express mail') — it cannot describe general speed. 'Swift' is more literary and suggests smooth, effortless speed ('a swift response'). For example, you would say 'a high-speed train' is 'fast', but you would not call it 'express' unless it makes few stops. A 'rapid' recovery from illness would not be called 'high-speed' because recovery is a process, not a machine.

fast ↗rapid ↗express ↗swift ↗

Common collocations

Nouns

Phrases

  • at high speed
  • reach high speed
  • high-speed rail

Prepositions

  • at (high speed)

Etymology

Old EnglishMiddle EnglishModern English

The compound 'high speed' combines two Old English words. 'High' comes from Old English 'hēah', meaning tall or lofty — it has been used since the 1200s to mean 'great in degree or intensity'. 'Speed' comes from Old English 'spēd', which originally meant prosperity, success, or good fortune. By the 1300s, 'speed' had shifted to mean rate of motion or velocity. The two words began appearing together in the 1800s with the rise of fast transport, first as a noun phrase ('at high speed') and later as a hyphenated compound adjective ('high-speed') describing trains, machinery, and eventually digital technology.