A synonym for cycles per second.

Hertz, Heinrich Rudolf 1857-94, German physicist. He confirmed James Clerk Maxwell's electromagnetic theory and produced and studied electromagnetic waves, which he showed are long transverse waves that travel at the speed of light and can be reflected, refracted, and polarized like light. The unit of frequency, the hertz, is named for him.

In electrical/electronic applications with alternating current, a unit of frequency where 1Hz equal one cycle per second.