Hertz n 1: the unit of frequency; one Hertz has a periodic interval of one second [syn: {Hz}, {cycle per second}, {cycles/second}, {cps}, {cycle}] 2: German physicist who was the first to produce electromagnetic waves artificially (1857-1894) [syn: {Heinrich Hertz}, {Heinrich Rudolph Hertz}] 3: German physicist who with James Franck proved the existence of the stationary energy states postulated by Bohr (1887-1975) [syn: {Gustav Hertz}, {Gustav Ludwig Hertz}]