<p><strong>Noun</strong></p><ul><li>William Thomson, 1st Baron, 1824–1907, English physicist and mathematician.</li><li>The basic unit of temperature in the International System of Units (SI), formally defined to be approximately 1/273 of the triple point of water.</li><li>K</li></ul><p><strong>Adjective</strong></p><ul><li>Noting or pertaining to an absolute scale of temperature (Kelvin scale) in which the degree intervals are equal to those of the Celsius scale and in which absolute zero is 0 degrees Kelvin and the triple point of water has the value of approximately 273 degrees Kelvin.</li></ul>