noun · common

horse power

horse power · horse powers

Any of a class of machines that used draft horses as a source of power to an output…Any of a class of machines that used draft horses as a source of power to an output shaft or sheave. Treadmill types and merry-go-round–like types existed.

Meaning

2 senses

(dialectal, historical)Any of a class of machines that used draft horses as a source of power to an output shaft or sheave. Treadmill types and merry-go-round–like types existed.
In that era, they powered their corn sheller and their thresher with a horse power.
Used other than figuratively or idiomatically: motive effort supplied by one or more horses.
In the 1920s through 1940s, the push for power farming aimed to replace horse power with tractor power on the farm.