KILOCALORIE
Calorie, kilogram calorie, kilocalorie, large calorie, nutritionist's calorie
(noun) a unit of heat equal to the amount of heat required to raise the temperature of one kilogram of water by one degree at one atmosphere pressure; used by nutritionists to characterize the energy-producing potential in food
Source: WordNet® 3.1
Etymology
Noun
kilocalorie (plural kilocalories)
a non-SI unit of energy equal to 1,000 calories, used (now rare) in chemistry or physics; equal to 1 calorie or Calorie as used in nutrition. Symbol kcal.
Usage notes
This prefix kilo- is generally applied to the small calorie, and not to the large calorie used in nutrition, to avoid confusion because 1,000 food calories would be 1,000,000 small calories.
Source: Wiktionary