- A unit interval on the Kelvin scale.
"The interval between the freezing and boiling points of water is 100 kelvins."
- In the International System of Units, the base unit of thermodynamic temperature; 1/273.16 of the thermodynamic temperature of the triple point of water. Shown as "K".
- (usually as postpositioned adjective) A unit for a specific temperature on the Kelvin scale.
"Water boils above 373.15 kelvin."
"Ice melts above 273.15 kelvin."