frequency

Từ điển Oxford Advanced Learner 8th

fre·quency [frequency frequencies] BrE [ˈfriːkwənsi] NAmE [ˈfriːkwənsi] noun (pl. fre·quencies)
1. uncountable, countable the rate at which sth happens or is repeated
•Fatal road accidents have decreased in frequency over recent years.
•a society with a high/low frequency (= happening often/not very often) of stable marriages
•The program can show us word frequency (= how often words occur in a language).
2. uncountable the fact of sth happening often
•the alarming frequency of computer errors
•Objects like this turn up at sales with surprising frequency.
3. countable, uncountable (technical)the rate at which a sound or ↑electromagnetic wave ↑vibrates (= moves up and down)
•a high/low frequency
4. countable, uncountable (technical)the number of radio waves for every second of a radio signal
•a frequency band
•There are only a limited number of broadcasting frequencies.

Word Origin:
mid 16th cent. (gradually superseding late Middle English frequence; originally denoting a gathering of people): from Latin frequentia, from frequens, frequent- ‘crowded, frequent’.

Example Bank:
•Bullets bounced off the rock with alarming frequency.
•Crime increases in frequency in less settled neighbourhoods.
•The drug can reduce the frequency and severity of attacks.
•The relative frequency of this illness in the area is of concern to all doctors.
•These incidents have increased in frequency.