horsepower

horsepower — noun

1. a standard unit used to express the output strength of an engine or motor, based

1.nounB1
Definition

a standard unit used to express the output strength of an engine or motor, based on how much work it can do — for example, a car with 200 horsepower can pull much more weight than a car with 100 horsepower

Example

The new sports car has 400 horsepower and reaches sixty in under four seconds.

number + horsepower for engine performance specs

Luca's motorcycle does not have enough horsepower to climb the steep mountain road easily.

enough + [unit] + to-infinitive for capability

Common collocations
  • enough horsepower
  • high / low horsepower
  • horsepower rating
  • more / less horsepower
  • increase / boost horsepower
Synonyms
  • power

    more general term; horsepower is a specific unit, while power can refer to any measure of energy output

  • hp

    standard abbreviation used in technical specs and writing

Grammar Patterns

[number] + horsepower

enough + horsepower + to-infinitive

possessive + horsepower

Usage Note

Frequently used with a number (e.g., 200 horsepower). The word does not change form in the plural: you say 300 horsepower, not 300 horsepowers. Commonly shortened to 'hp' in writing. Appears in discussions about cars, trucks, motorcycles, boat motors, and other machinery where engine strength matters.

Common Mistakes

This engine has 200 horsepowers.
This engine has 200 horsepower.
'horsepower' stays the same whether you mean one unit or several hundred.

Synonym discussion

Sense: noun/1

Horsepower (hp) is a specific unit of power used mainly for engines and motors, while power is a broad term that can describe any rate of energy transfer. Torque is a different concept: it measures twisting or turning force, not overall work rate — an engine can have high torque but moderate horsepower. Wattage is the metric-system equivalent; one horsepower equals roughly 746 watts. In everyday conversation, horsepower is used for vehicles and machinery, whereas wattage is common for electrical devices like light bulbs or speakers. For example: 'This truck's high horsepower lets it pull a heavy load,' but 'The speaker's high wattage makes it very loud.'

horsepower ↗power ↗torque ↗wattage

Common collocations

Nouns

Phrases

  • a lot of horsepower
  • not enough horsepower
  • horsepower per tonne

Etymology

Englishcoinage by James Watt (Scottish, 18th century)

Coined in the late 1700s by Scottish engineer James Watt. He wanted a way to compare the output of his new steam engines with the familiar power of draft horses. After observing horses at work in a coal mine, he calculated that a strong horse could lift 550 pounds one foot in one second — and set one horsepower at 550 foot-pounds per second. The term survived long after engines replaced horses and is still the standard way people talk about engine strength today.