Definition of calorie
plural calories
1 a
: the amount of heat required at a pressure of one atmosphere to raise the temperature of one gram of water one degree Celsius that is equal to about 4.19 joules
—abbreviation cal
— called also
gram calorie, small calorie
b
: the amount of heat required to raise the temperature of one kilogram of water one degree Celsius : 1000 gram calories or 3.968 Btu
—abbreviation Cal
— called also
large calorie
2 a
: a unit equivalent to the large calorie expressing heat-producing or energy-producing value in food when oxidized in the body
b
: an amount of food having an energy-producing value of one large calorie
