[ free-kwuhn-see ]
/ ˈfri kwən si /
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See synonyms for: frequency / frequencies on Thesaurus.com

Definition of frequency

noun, plural fre·quen·cies.
Also frequence. the state or fact of being frequent; frequent occurrence: We are alarmed by the frequency of fires in the neighborhood.
rate of occurrence: The doctor has increased the frequency of his visits.
  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. Symbol: F; Abbreviation: freq.
Mathematics. the number of times a value recurs in a unit change of the independent variable of a given function.
Statistics. the number of items occurring in a given category.
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Origin of frequency

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


non·fre·quence, nounnon·fre·quen·cy, nouno·ver·fre·quen·cy, nounun·der·fre·quen·cy, noun, plural un·der·fre·quen·cies.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use frequency in a sentence

British Dictionary definitions for frequency

/ (ˈfriːkwənsɪ) /

noun plural -cies
the state of being frequent; frequent occurrence
the number of times that an event occurs within a given period; rate of recurrence
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 hertzSymbol: ν, f
  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)
  1. the number of individuals of a species within a given area
  2. the percentage of quadrats that contains individuals of a species
Also called (for senses 1, 2): frequence

Word Origin for frequency

C16: from Latin frequentia a large gathering, from frequēns numerous, crowded
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for frequency

[ frēkwən-sē ]

Physics The rate at which a repeating event occurs, such as the full cycle of a wave. Frequencies are usually measured in hertz. Compare amplitude. See also period.
Mathematics The ratio of the number of occurrences of some event to the number of opportunities for its occurrence.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for frequency


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.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.