frequency

American  

[free-kwuhn-see] / ˈfri kwən si /

noun

plural

frequencies

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

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

Etymology

Origin of frequency

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

Example Sentences

Adverse effects depend on the level of lead in the food, the age of the consumer and the frequency of exposure, according to the FDA.

From Los Angeles Times • Apr. 2, 2026

The company said it expects the program to increase visit frequency, improve retention, and attract new customers over time.

From Barron's • Apr. 1, 2026

British firm GSK doesn't list the frequency of side effects for its drug Ropinirole anywhere.

From BBC • Mar. 28, 2026

Instead of a single resonance signal, some disks produced a series of closely spaced lines, forming what is known as a frequency comb.

From Science Daily • Mar. 27, 2026

They can measure the frequency of notes, and like most measurements, these will be numbers, like "440 vibrations per second."

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

Related Words

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