frequency

noun

fre·​quen·​cy ˈfrē-kwən(t)-sē 

plural frequencies

1

: the fact or condition of occurring frequently

the frequency of automobile accidents

2

a

: the number of times that a periodic function repeats the same sequence of values during a unit variation of the independent variable

b

: the number, proportion, or percentage of items in a particular category in a set of data

3

: the number of repetitions of a periodic process in a unit of time: such as

a

: the number of complete alternations (see alternation sense 1) per second of an alternating current

b

: the number of complete oscillations (see oscillation sense 3) per second of energy (such as sound or electromagnetic radiation) in the form of waves

Synonyms of frequency

• prevalence
• frequence

Examples of frequency in a Sentence

the alarming frequency of serious automobile accidents caused by young drivers

The frequency of student errors was frustrating to the young teacher.

Our visits decreased in frequency.

Errors were occurring with increasing frequency.

a sound wave of high frequency

waves having very different frequencies from one another

a current having a frequency of 60 hertz

a radio frequency of 30 megahertz

Recent Examples on the Web

Speer Boulevard The project would install Bus Rapid Transit — high-frequency buses similar to trains — along a 13-mile route from Federal Boulevard to the Regional Transportation District’s Nine Mile Station near Interstate 225, transforming Speer, Leetsdale Avenue, and Parker Road. —Bruce Finley, Denver Post, 29 Mar. 2026

Everyone needed the same current Signal Operating Instructions with code names and frequencies. —Edward Lotterman, Twin Cities, 29 Mar. 2026

Due to increasing activity from the Anthelion sporadic meteor source (a broad region in the night sky that produces a steady, low-level stream of meteors year round) and maybe improved reporting, this amount reflects both a high total count and frequency. —Janet Loehrke, USA Today, 28 Mar. 2026

Despite the frequency of fatal crashes, the industry is important to the economy, Kauai Mayor Derek Kawakami said at a news conference Friday. —Arkansas Online, 28 Mar. 2026

Word History

First Known Use

1600, in the meaning defined at sense 1

Phrases Containing frequency

• extremely high frequency
• extremely low frequency
• frequency distribution
• frequency modulation
• frequency response
• gene frequency
• high frequency
• low frequency
• medium frequency
• radio frequency
• superhigh frequency
• ultrahigh frequency
• very high frequency
• very low frequency

Rhymes for frequency

• infrequency
• multifrequency

Kids Definition

frequency

noun

fre·​quen·​cy ˈfrē-kwən-sē 

plural frequencies

1

: the fact or condition of happening often

2

: how often something happens : rate of repetition

3

: the number of repetitions of a periodic process in a unit of time: as

a

: the number of times per second that an electric current flowing in one direction changes direction then changes back

a current having a frequency of 60 hertz

b

: the number of waves (as of sound or electromagnetic energy) that pass a fixed point each second

a sound having a frequency of 1500 hertz

the frequency of yellow light

4

: the number or proportion of one kind of item in a group

the frequency of chocolate doughnuts in the box

Medical Definition

frequency

noun

fre·​quen·​cy ˈfrē-kwən-sē 

plural frequencies

1

: the number of individuals in a single class when objects are classified according to variations in a set of one or more specified attributes

2

: the number of repetitions of a periodic process in a unit of time