The repeated occurrence of a thing at short intervals or periods.

频繁。

The number of times an occurrence is repeated in a given period.

发生次数。

The number of cycles per second of an electric current produced by an alternating generator.

【电】周率；频率。频率是每单位时间内，波动完成完整振动的次数。频率与周期的关系为倒数。频率的单位是赫兹(Hz)。