frequency 
 noun (frequenc, ies)
 (uncountable) The rate of occurrence of anything; the relationship between incidence and time period.
 With growing confidence, the Viking"s raids increased in .
 The of bus service has been improved from 15 to 12 minutes.
 (uncountable) The property of occurring often rather than infrequently.
 The FAQ addresses questions that come up with some .
 The of the visits was what annoyed him.
 (countable) The quotient of the number of times <math>n</math> a periodic phenomenon occurs over the time <math>t</math> in which it occurs: <math>f = n / t</math>.
 The of middle C is 440 oscillations per second.
 The of a wave is its velocity <math>v</math> divided by its wavelength <math>\lambda</math>: <math>f = v / \lambda</math>.
 Broadcasting live at a of 98.3 megahertz, we"re your rock alternative!
 The for electric power in the Americas is generally 60 Hz rather than 50.''

