horse·pow·er 
(hôrspou′ər)
(hôrspou′ər)n. pl. horse·power
1. Abbr. hp A unit of power in the US Customary System, equal to 745.7 watts or 33,000 foot-pounds per minute.
2. The power exerted by a horse in pulling.
3. Informal Effective strength: political horsepower; computer horsepower.