noun
: a practical temperature scale defining all temperatures above -183° C by specified formulas relating temperatures at one atmosphere pressure to the indications of instruments calibrated at six reproducible fixed points: the boiling point of oxygen (-182.97° C), the ice point (0° C), the steam point (100° C), the boiling point of sulfur (444.6° C), the freezing point of silver (960.8° C), the freezing point of gold (1063° C)