(Celsius). The internationally used scale for measuring temperature, in which 100 degrees is the boiling point of water at sea level (1 atm) and 0 degrees is the freezing point. A temperature given in centigrade degrees may be converted to the corresponding Fahrenheit temperature by multiplying it by 9/5 (or 1.8) and adding 32 to the product. A temperature given in Fahrenheit degrees is converted to the corresponding centigrade temperature by subtracting 32 and multiplying the remainder by 5/9. The centigrade scale was devised by the Swedish scientist Celsius; his name is officially used to designate it, even though centigrade is more meaningful.