### noun

**(1) **The number of observations in a given statistical category

**(2) **The ratio of the number of observations in a statistical category to the total number of observations

**(3) **The number of occurrences within a given time period

"The frequency of modulation was 40 cycles per second"

"The frequency of his seizures increased as he grew older"

### Noun

- The rate of occurrence of anything; the relationship between incidence and time period.
- With growing confidence, the Viking’s raids increased in
**frequency**.
- The
**frequency** of bus service has been improved from 15 to 12 minutes.

- The property of occurring often rather than infrequently.
- The FAQ addresses questions that come up with some
**frequency**.
- The
**frequency** of the visits was what annoyed him.

- The quotient of the number of times $n$ a periodic phenomenon occurs over the time $t$ in which it occurs: $f\; =\; n\; /\; t$.
- The
**frequency** of the musical note A above middle C is 440 oscillations per second.
- The
**frequency** of a wave is its velocity $v$ divided by its wavelength $\backslash lambda$: $f\; =\; v\; /\; \backslash lambda$.
- Broadcasting live at a
**frequency** of 98.3 megahertz, we’re your rock alternative!
- The
**frequency** for electric power in the Americas is generally 60 Hz rather than 50.