■ noun ( plural ~s )
1》 (also small ~ ) the energy needed to raise the temperature of 1 gram of water through 1°C (now usually defined as 4.1868 joules).
2》 (also large ~ ) the energy needed to raise the temperature of 1 kilogram of water through 1°C, equal to one thousand small ~s and often used to measure the energy value of foods.
Origin
C19: from Fr., from L. calor 'heat' + -ie (see -y 3 ).