horsepower

Definition

Power derived from the motion of a horse.

Etymology

From horse + power: the unit was originally defined as the amount of power that a horse could provide. Both non-metric and metric units of power were derived from effectively identical measurements of the power a draught horse could sustain over several hours, with the difference in watts solely due to different rounding errors to express that power in round numbers in the original non-SI units (ft·lbf/min and kgf⋅m/s respectively).

Example Sentences

• "Shillibeer's bus came in 1829 drawn by three horses. Later two horses were found sufficient to pull these closed wagonettes, which eventually had outside seats, and later on the substitution of a motor for horsepower."
• "The Sun Inn is an attractive black-and-white building, and has an old mounting block outside as a reminder of the days when horsepower meant four legs and a saddle."
• "The wheel was to have been turned by horsepower, but it was adapted to be driven by a mill-wheel on the river Derwent […]"