Definition of frequency has definitions from the fields of mathematics,statistics,physics 1 [ noun ] (physics) the number of occurrences within a given time period (usually 1 second) Synonyms Examples "the frequency of modulation was 40 cycles per second" Used in print(High Fidelity, 11:10...) The effect of the recording is very open and natural , with the frequency emphasis exactly what you would expect from a live performance . (Nathan Rapport, ""I've Been Here before!"...) We know that the number of radio and television impulses , sound_waves , ultra-violet rays , etc. , that may occupy the very same space , each solitary upon its own frequency , is infinite . (James A. Ibers et al., "Proton magnetic resonance...) A modulation frequency of 40 cps with an amplitude as small as possible , commensurate with reasonably good signal-to-noise quality , was used . 2 [ noun ] (statistics) the ratio of the number of observations in a statistical category to the total number of observations Synonyms Used in print(Nathan Rapport, ""I've Been Here before!"...) So we may conceive the coexistence of the infinite number of universal , apparently momentary states_of_matter , successive one_after_another in consciousness , but permanent each on its own basic phase of the progressive frequencies . Three seconds flat is the usual time , and the space is crossed by moderate mileage , while the overwhelming immensity of such journeys must be conceived as a static pulsation through an enormous number of coexistent frequencies which perpetuate all events . The body , senses and brain , in_common_with all matter , have their counterpart on each of a countless number of frequencies . The senses in each counterpart bear the impression only of phenomena that share its own frequency , whereas those upon all other frequencies are invisible , inaudible and intactible to them . The senses in each counterpart bear the impression only of phenomena that share its own frequency , whereas those upon all other frequencies are invisible , inaudible and intactible to them . Related terms 3 [ noun ] (mathematics) the number of observations in a given statistical category Synonyms Used in print(E. Gellhorn, "Prolegomena to a theory of the emotions"...) On_the_other_hand , the temporary reduction in hypothalamic excitability through the injection of a barbiturate into the posterior hypothalamus causes a lessening in frequency and amplitude of cortical strychnine spikes until the hypothalamic excitability is restored . Related terms * Phonetic and Homophones Similar Spelling To share this definition click "text" (Facebook, Twitter) or "link" (blog, mail) then paste text link