frequency

noun (plural frequencies)

• 1the rate at which something occurs or is repeated over a particular period of time or in a given sample:shops have closed with increasing frequency during the period
• the fact of being frequent or happening often.
• Statistics the ratio of the number of actual to possible occurrences of an event.
• Statistics the (relative) number of times something occurs in a given sample.

• 2the rate at which a vibration occurs that constitutes a wave, either in a material (as in sound waves), or in an electromagnetic field (as in radio waves and light), usually measured per second. (Symbol: f or ν)
• the particular waveband at which a radio station or other system broadcasts or transmits signals.