We don't have synonyms for horse-power yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are horsepower, horse power and horse-coper.
(n) :
Alternative spelling of horsepower. [(literally, uncountable) Power derived from the motion of a horse.]
(n) :
Obsolete spelling of horse power. [(chiefly historical, dialectal) 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.]
(n) :
Alternative spelling of horsepower. [(literally, uncountable) Power derived from the motion of a horse.]
(n) :
Obsolete spelling of horse power. [(chiefly historical, dialectal) 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.]