1) General subject: horseback
2) American: soup, squirrel (I got 440 squirrels and a gaggle of carburetors)
3) Engineering: horse, horse-power, horsepower, (PferdeStark, по-немецки, система DIN) PS (http://forum.lingvo.ru/actualthread.aspx?bid=18&tid=35213&hl=equivalent)
4) Construction: horse power
6) Automobile industry: hp
7) Metrology: horsepower (745,7 Вт; Великобритания), metric horsepower
8) Coolers: horsepower (единица измерения мощности)
9) Drilling: HP (horsepower)
10) Sakhalin energy glossary: horse power (unit of power equal to 746 watts and nearly equivalent to the English gravitational unit of the same name that equals 550 foot-pounds of work per second [10.70 kg-calories per minute]) (HP, hp; л.с.), horsepower-hour (hp-hr; л.с.)
11) Chemical weapons: horsepower (HP)
12) Yachting: h.p.
Универсальный русско-английский словарь. Академик.ру. 2011.