horsepower

American  

[hawrs-pou-er] / ˈhɔrsˌpaʊ ər /

noun

1. a foot-pound-second unit of power, equivalent to 550 foot-pounds per second, or 745.7 watts.

2. Informal. the capacity to achieve or produce; strength or talent.

   The university's history faculty is noted for its intellectual horsepower.

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horsepower British  

/ ˈhɔːsˌpaʊə /

noun

1. an fps unit of power, equal to 550 foot-pounds per second (equivalent to 745.7 watts)

2. a US standard unit of power, equal to 746 watts

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horsepower Scientific  

/ hôrs′pou′ər /

1. A unit that is used to measure the power of engines and motors. One unit of horsepower is equal to the power needed to lift 550 pounds one foot in one second. This unit has been widely replaced by the watt in scientific usage; one horsepower is equal to 745.7 watts.

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horsepower Cultural  

1. A unit of power equal to about 746 watts.

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Discover More

The horsepower is used to measure the power of engines.

This term was coined by James Watt, who invented a new type of steam engine in the eighteenth century. Watt found that the horse could do a certain amount of work per second; when he sold his steam engines, this measurement allowed him to estimate the worth of an engine in terms of the number of horses it would replace. Therefore, a six-horsepower engine was capable of replacing six horses.

Etymology

Origin of horsepower

First recorded in 1800–10; horse + power

Compare meaning

How does horsepower compare to similar and commonly confused words? Explore the most common comparisons:

• brake horsepower vs. horsepower

Example Sentences

See Examples For:

horsepower

Outboard motors are generating unprecedented horsepower as boat owners demand larger and faster vessels.

From The Wall Street Journal ● Jul. 27, 2026

DFSX’s software-defined architecture aligns with a broader shift from raw horsepower to specialized efficiency.

From The Wall Street Journal ● Jul. 14, 2026

He said the finished car would have about 1,600 horsepower in total.

From BBC ● Jun. 1, 2026

Demand may also need time to catch up with that extra datacenter horsepower, while macro cycles are still an important consideration.

From MarketWatch ● May 28, 2026

But by 1903, automotive horsepower had greatly improved— one car averaged 65.3 mph in a cross-European race that season—making the races a good spectacle.

From "Seabiscuit: An American Legend" by Laura Hillenbrand

Related Words

• dynamism
• electricity
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