1.nounIn 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".
2.nounA unit interval on the Kelvin scale.
"The interval between the freezing and boiling points of water is 100 kelvins."
3.noun(usually as postpositioned adjective) A unit for a specific temperature on the Kelvin scale.