/ Dictionary / Index H horsepower-hour: Meaning and Definition of Find definitions for: horse•pow•er-hour Pronunciation: (hôrs'pou"ur-our", -ou"ur), [key] — n. a foot-pound-second unit of energy or work, equal to the work done by a mechanism with a power output of one horsepower over a period of one hour. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: horsepower-hour (Thesaurus) horsepower horsepox Related Content Daily Word Quiz: intrepid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language