(1) The number of waves per second that a transmitter radiates, measured in kilohertz (KHz) and megahertz (MHz). The FCC assigns to each TV and radio station the frequency on which it may operate, to prevent interference with other stations. (2) Of media exposure the number of times an individual or household is exposed to a medium within a given period of time. (3) In statistics the number of times each element appears in each step of a distribution scale.