[cal.o.rie] also cal.o.ry n, pl -ries [F calorie, fr. L calor heat, fr. calere to be warm--more at lee] (1866) 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--called also gram calorie, small calorie--abbr. cal 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--called also large calorie--abbr. Cal
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