A nonmetric 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.
Strength.
Power derived from the motion of a horse.
A metric unit (symbol often PS from the German abbreviation), approximately equal to 735.5 watts.
An amount or power (especially electric), expressed in watts, kilowatts etc.
The power requirement of some electric appliance.