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.
A metric horsepower (symbol often PS from the German abbreviation), approximately equal to 735.5 watts.
Strength
The total number of all available workers; the workforce.
The power exerted by a single person (analogous to horsepower.)
2018年3月22日 — manpower development programme, formulating and coordinating ... cycle: A motorcycle with a motor that produces 5 brake horsepower or less.