[1] : The Collaborative International Dictionary of English v.0.48

frequency \fre"quency\, n.; pl. frequencies. l. frequentia
   numerous attendance, multitude: cf. f. fr'equence. see
   frequent.
   1. the condition of returning frequently; occurrence often
      repeated; common occurence; as, the frequency of crimes;
      the frequency of miracles.
      1913 webster

            the reasons that moved her to remove were, because
            rome was a place of riot and luxury, her soul being
            almost stifled with, the frequencies of ladies'
            visits.                               --fuller.
      1913 webster

   2. a crowd; a throng. obs. --b. jonson.
      1913 webster
see also:
frequencies frequent 

[2] : WordNet (r) 2.0

frequency
     n 1: the number of occurrences within a given time period
          usually 1 second; "the frequency of modulation was 40
          cycles per second" syn: frequence, oftenness
     2: the ratio of the number of observations in a statistical
        category to the total number of observations syn: relative
        frequency
     3: the number of observations in a given statistical category
        syn: absolute frequency
see also:
frequence oftenness relative frequency absolute frequency 

[3] : Moby Thesaurus II by Grady Ward, 1.0

93 moby thesaurus words for "frequency":
   af, cps, ehf, hf, hz, mf, rf, shf, uhf, vhf, vlf, amplitude,
   antinode, audio frequency, carrier frequency, crest, cycles,
   de broglie wave, diffraction, electromagnetic radiation,
   electromagnetic wave, extremely high frequency, fluctuation,
   frequency band, frequency spectrum, fundamental, fundamental tone,
   guided wave, harmonic, harmonic motion, hertz, high frequency,
   in phase, interference, intermediate frequency, intonation,
   kilocycles, kilohertz, libration, light, longitudinal wave,
   low frequency, lower frequencies, mechanical wave,
   medium frequency, megacycles, megahertz, monotone, monotony, node,
   nutation, oscillation, out of phase, overtone, partial,
   partial tone, pendulation, period, periodic wave, periodicity,
   pitch, radio frequency, radio wave, ray, reinforcement, resonance,
   resonance frequency, seismic wave, shock wave, sound wave,
   spark frequency, spectrum, superhigh frequency, surface wave,
   tidal wave, tone, tonelessness, transverse wave, trough,
   ultrahigh frequency, upper frequencies, vacillation,
   very high frequency, very low frequency, vibrancy, vibratility,
   vibration, wave, wave equation, wave motion, wave number,
   wavelength, wavering

Frequency >> F Words
Frequency, definition of term: Frequency
frequency_pag1.html

Frequency Shift >> F Words
Frequency Shift, definition of term: Frequency Shift
frequency+shift_pag1.html

Frequency Modul >> F Words
Frequency Modul, definition of term: Frequency Modul
frequency+modul_pag1.html

Frequency Divis >> F Words
Frequency Divis, definition of term: Frequency Divis
frequency+divis_pag1.html

Frequency Distr >> F Words
Frequency Distr, definition of term: Frequency Distr
frequency+distr_pag1.html

Radio Frequency >> R Words
Radio Frequency, definition of term: Radio Frequency
radio+frequency_pag1.html

High Frequency >> H Words
High Frequency, definition of term: High Frequency
high+frequency_pag1.html