horsepower

horse-pow-er · noun

imported

Definitions

noun

  1. 1.

    A unit of power equal to 550 foot-pounds per second (745.7 watts), originally defined to compare the output of steam engines with the power of draft horses.

  2. 2.

    The power output or rate of work of an engine or motor.

Forms

plural: horsepower

Related words

See also: engine, motor, power, watt
Synonyms: engine power, power

Etymology

Coined by Scottish engineer James Watt in the late 18th century to compare the output of steam engines with the power of horses. Watt calculated that a horse could do 33,000 foot-pounds of work per minute. Abbreviated as "hp."