calorie
From Glossary of Meteorology
(Abbreviated cal.) A unit of energy defined as that amount of energy required to raise the temperature of one gram of water by one degree Celsius (the gram-calorie or small calorie), equal to 4.1855 joules.
The kilogram calorie or large calorie (Kcal, kg-cal, or Cal) is 1000 times as large as a calorie.