frequency

American  

[free-kwuhn-see] / ˈfri kwən si /

noun

• frequencies
  plural

1. Also frequence. the state or fact of being frequent; frequent occurrence.

   We are alarmed by the frequency of fires in the neighborhood.

   Synonyms:

   recurrence, repetition, regularity

2. rate of occurrence.

   The doctor has increased the frequency of his visits.

3. Physics.

   1. the number of periods or regularly occurring events of any given kind in unit of time, usually in one second.

   2. the number of cycles or completed alternations per unit time of a wave or oscillation. F; freq.

4. Mathematics. the number of times a value recurs in a unit change of the independent variable of a given function.

5. Statistics. the number of items occurring in a given category.

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frequency British  

/ ˈfriːkwənsɪ /

noun

1. the state of being frequent; frequent occurrence

2. the number of times that an event occurs within a given period; rate of recurrence

3. ν, f. physics the number of times that a periodic function or vibration repeats itself in a specified time, often 1 second. It is usually measured in hertz

4. statistics

   1. the number of individuals in a class ( absolute frequency )

   2. the ratio of this number to the total number of individuals under survey ( relative frequency )

5. ecology

   1. the number of individuals of a species within a given area

   2. the percentage of quadrats that contains individuals of a species

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frequency Scientific  

/ frē′kwən-sē /

1. Physics The rate at which a repeating event occurs, such as the full cycle of a wave. Frequencies are usually measured in hertz.

2. Physics Compare amplitude See also period

3. Mathematics The ratio of the number of occurrences of some event to the number of opportunities for its occurrence.

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frequency Cultural  

1. In physics, the number of crests of a wave that move past a given point in a given unit of time. The most common unit of frequency is the hertz (Hz), corresponding to one crest per second. The frequency of a wave can be calculated by dividing the speed of the wave by the wavelength. Thus, in the electromagnetic spectrum, the wavelengths decrease as the frequencies increase, and vice versa.

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Other Word Forms

Derived Forms

• nonfrequence
  noun
• nonfrequency
  noun
• overfrequency
  noun
• underfrequency
  noun

Inflected Forms

Nouns

• frequencies
  plural

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Etymology

Origin of frequency

First recorded in 1545–55, frequency is from the Latin word frequentia assembly, multitude, crowd. See frequent, -cy

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Explanation

Frequency measures how often things repeat over time. City buses often reach stops at a frequency of every 15 minutes, unless it's snowing or raining really hard. In that case, the frequency will slow. You probably know the word frequent, a synonym for often. So, it is tempting to think frequency describes something that happens often. However, this isn't true: frequency describes any rate of time at which something repeats. For example, from Earth, Halley's Comet is visible at a frequency of 76 years — it's not frequent, but it is on schedule.

Example Sentences

See Examples For:

frequency frequencies

In 2023, a clinical trial of 121 people in the UK found they experienced, on average, a reduction in tic frequency of 25% while using a prototype of the device.

From BBC ● Nov. 12, 2026

According to the since-removed listing, the home was outfitted with “a state-of-the-art medical-grade air filtration system,” electromagnetic frequency shielding around the primary bedroom, a saltwater pool, and a “regenerative orchard.”

From MarketWatch ● Nov. 10, 2026

To get those big numbers, you’ve got to bowl with frequency and we only go maybe once or twice a week.

From Los Angeles Times ● Nov. 6, 2026

Instead of relying on a conventional wired power connection, the implant receives energy wirelessly at a frequency of 13.56 MHz.

From Science Daily ● Nov. 2, 2026

NOTE: If you have been looking at the harmonic series above closely, you may have noticed that some notes that are written to give the same interval have different frequency ratios.

From "Understanding Basic Music Theory" by Catherine Schmidt-Jones and Russel Jones

The company said higher claims frequencies and average severities, in addition to lower average earned premiums per policy, hurt the unit.

From MarketWatch ● Nov. 9, 2026

“We call it a dimensional tuner. You can look at higher frequencies and see if there’s any fae spirits around, or down-tune it and see if there’s any undead spirits or demons around.”

From Los Angeles Times ● Nov. 6, 2026

Using measurements from Juno, researchers discovered that Jupiter relies on plasma waves with multiple frequencies to slow and heat incoming solar particles.

From Science Daily ● Oct. 29, 2026

It also suggests having a FM radio for updates during outages, and writing down the frequencies of any national or local radio stations you use for news.

From BBC ● Oct. 22, 2026

On the other hand, sounds that have too many frequencies, like the sound of glass breaking or of ocean waves crashing on a beach, may be interesting and even pleasant.

From "Understanding Basic Music Theory" by Catherine Schmidt-Jones and Russel Jones

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Related Words

• density
• number
• prevalence
• recurrence
• regularity
• repetition

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