fre·quen·cy 
/ˈfri:kwənsi/ noun
plural fre·quen·cies /ˈfri:kwənsi/ noun 1 [noncount] : the fact or condition of happening often : common occurrence
▪ the alarming frequency of serious automobile accidents caused by young drivers ▪ The frequency of student errors was frustrating to the young teacher. 2 [noncount] : the number of times that something happens during a particular period
▪ The frequency of our visits decreased [=our visits occurred less often] during the school year. ▪ Our visits decreased in frequency. ▪ Errors were occurring with increasing frequency. ▪ high/low frequency 3 technical : the number times that something (such as a sound wave or radio wave) is repeated in a period of time (such as a second) [noncount] ▪ a sound wave of high/low frequency [count] ▪ waves having very different frequencies from one another ▪ high/low frequencies ▪ a current having a frequency of 60 hertz ▪ a radio frequency of 30 megahertz
▪ the alarming frequency of serious automobile accidents caused by young drivers ▪ The frequency of student errors was frustrating to the young teacher.
▪ The frequency of our visits decreased [=our visits occurred less often] during the school year. ▪ Our visits decreased in frequency. ▪ Errors were occurring with increasing frequency. ▪ high/low frequency
