- noun a unit of power equal in the UK to 550 foot-pounds per second and in the USA to 745.7 watts.
- noun the accepted unit for measuring the rate of doing work
- A unit measurement of power or energy in the United States Customary System. Mechanically, a single horsepower represents 550 foot-pounds per second. Electrically, a single horsepower represents 746 watts.
- A unit of power equal to approximately 745.6999 watts. Its abbreviation is hp.