- Unit of frequency, signifying one cycle (such as a complete wave of electromagnetic radiation) per second
(written as Hertz)the SI unit of frequency, defined as the number of cycles per second of time.
- The SI unit of frequency. It is equal to one complete cycle of a periodic phenomenon, such as an electromagnetic wave, per second. Frequencies are expressed in multiples of hertz, such as kilohertz, terahertz, and so on. It is equivalent to cycles per second, which is an obsolescent term. Hertz contrasts with becquerel, which measures phenomena that occur in an unpredictable manner, such as radioactive disintegrations. Its abbreviation is Hz.