查询结果:

n. 频率;经常发生,频繁;(声波或无线电波的)振动频率;波段  

来源于拉丁语frequens, frequent-(拥挤的,频繁的)、frequentia。

拆分: frequ拥挤,频繁 + -ency名词词尾   

例:
Accidents of this sort are happening with increasing frequency. 这类事故发生得越来越频繁。 
Fatal accidents have decreased in frequency over recent years. 近年来死亡事故发生的频率已经下降。 
Accidents are happening with increasing frequency. 事故发生得越来越频繁。 
If we can know their frequency we will monitor their talking. 如果我们知道他们的频率, 我们就能监听他们的谈话。