Etymology

• From horse and power, the unit originally defined as the amount of power that a horse could provide.

Noun

1. A non-metric unit of power (symbol hp) with various definitions, for different applications. The most common of them is probably the mechanical horsepower, approximately equal to 745.7 watts.
2. A metric horsepower (symbol often PS from the German abbreviation), approximately equal to 735.5 watts.
3. Strength

   political horsepower