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

Etymology

Origin of frequency

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

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

Decreasing auto repair costs and frequency of collisions have also allowed State Farm to lower auto rates in recent months by an average of 10% in 40 states.

From Los Angeles Times ● Aug. 19, 2026

Definitely check the meeting logs of the condo association to see what special assessments it has had recently, and at what frequency.

From MarketWatch ● Aug. 19, 2026

"The frequency of marks likely made by Purussaurus suggests that it was an important predator in these tropical ecosystems," Wilson comments.

From Science Daily ● Aug. 19, 2026

The only problem is that it doesn’t happen with quite the same frequency anymore.

From The Wall Street Journal ● Aug. 18, 2026

Figure 6.6: Remember that, no matter what note you start on, the note one octave higher has 2 times its frequency.

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

An FAA spokeswoman said the agency’s leadership met with the White House Military Office’s helicopter unit after the incident and is working to enhance coordination and boost radio signal frequencies.

From The Wall Street Journal ● Aug. 12, 2026

Timely communication was a concern at times, the report said, with the department lacking a necessary number of radio wave frequencies.

From Los Angeles Times ● Aug. 12, 2026

Because the source generates intense terahertz radiation that can be tuned to different frequencies, the researchers were able to change the material's optical properties, especially its reflectivity, both strongly and rapidly.

From Science Daily ● Jul. 31, 2026

The cochlea inside the inner ear naturally creates faint sounds at different frequencies, generally between about 500 and 5000 Hertz.

From Science Daily ● Jul. 19, 2026

This is one reason why most musicians prefer to talk in terms of cents and intervals instead of frequencies.

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

Related Words

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