calorie [M19th] Latin calor ‘heat’ is the source of calorific [L17th] and calorie. The related Latin calidarium ‘hot bath’ gives us, via French, the cauldron [ME] for cooking in, while the French form chaudière is the probable source of chowder [M17th]. Nonchalant [M18th] is a direct borrowing from French, going back to the Latin verb calere ‘to be warm’, and literally means ‘unheated, cool’.