frequency

frequency (ˈfriːkwənsɪ)

—n , pl -cies
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.	physics ν, f 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
	a. the number of individuals in a class (absolute frequency)
	b. the ratio of this number to the total number of individuals under survey (relative frequency)
5.	ecology
	a. the number of individuals of a species within a given area
	b. the percentage of quadrats that contains individuals of a species

[C16: from Latin frequentia a large gathering, from frequēns numerous, crowded]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source

Etymonline

Word Origin & History

frequency

1640s, "fact of occurring often," from L. frequentia (see frequent). Earlier it had been used in a now-bsolete sense of "state of being crowded" (mid-16c.); sense in physics, "rate of recurrence," especially of a vibration, is from 1831. In radio electronics, frequency

modulation (1922, abbreviated F.M.) as a system of broadcasting is distinguished from amplitude modulation (or A.M.).

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source

American Heritage

Science Dictionary

frequency

(frē'kwən-sē) Pronunciation Key

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.

American Heritage

Cultural Dictionary

frequency definition

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.

Example sentences

The magazine rapidly expanded in both publishing frequency and circulation size.

Within this context light has a frequency and a wavelength but it comes to us

in a series of discontinuous pulses.

However the average cheap mobile uses sophisticated frequency hopping that

makes eavesdropping difficult or near impossible.

Natural selection was now recognized as a change in the frequency of genes in a

population.

Enjoy Dictionary.com ad-free! Learn more

crystal fundamental frequency gene frequency heterodyne pink noise resonance

Matching Quote

"Every European visitor to the United States is struck by the comparative rarity of what he would call a face, by the frequency of men and women who look like elderly babies. If he stays in the States for any length of time, he will learn that this cannot be put down to a lack of sensibility—the American feels the joys and sufferings of human life as keenly as anybody else. The only plausible explanation I can find lies in his different attitude to the past. To have a face, in the European sense of the word, it would seem that one must not only enjoy and suffer but also desire to preserve the memory of even the most humiliating and unpleasant experiences of the past."

-W.H. Auden