What is the define of the word calorie?

Answer 1

The Calorie (the upper case "C" is relevant) is an obsolete pre-SI Metric unit defined as the amount of heat required to raise one kilogram of water one degree Celcius. As this amount depends on the starting temperature, one Calorie (strictly speaking, a kilocalorie) varies in value (approximately4.2 Joules) and has only been specifically defined as a Thermochemical Calorie (4.184 J exactly). Calorie continues in use only as a unit of food energy. Technically, "calorie" (lower case "c") is a gram calorie with a value one-thousanth of a Calorie, however, the distinction is often not made. The word calorie derives from Latin, via French "calor" meaning heat.