Meaning of FREQUENCY in English

fre ‧ quen ‧ cy /ˈfriːkwənsi/ BrE AmE noun ( plural frequencies )

[ Word Family: verb : ↑ frequent ; noun : ↑ frequency ≠ ↑ infrequency ; adverb : ↑ frequently ≠ ↑ infrequently ; adjective : ↑ frequent ≠ ↑ infrequent ]

1 . [uncountable] the number of times that something happens within a particular period of time or within a particular group of people

frequency of

the frequency of serious road accidents

the high/low frequency (of something)

the higher frequency of diabetes in older people

Side effects from prescribed drugs are being reported with increasing frequency (=more and more often) .

The relative frequency of fraternal twins has halved since 1950.

2 . [uncountable] the fact that something happens a lot SYN regularity :

Businesses come and go with alarming frequency.

3 . [uncountable and countable] technical the number of radio waves, sound waves etc that pass any point per second:

This station broadcasts on three different frequencies.

high/low frequency

Dolphins produce a high frequency sound.

the frequency range of the human ear

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.