Noun

(frequencies)

(uncountable) 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.

(uncountable) 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.

(countable) 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.

(statistics) number of times an event occurred in an experiment (absolute frequency)

Noun

(urgencies)

The quality or condition of being urgent; insistence; pressure; as, the urgency of a demand or an occasion.

* {{quote-news

, year=2011 , date=September 24 , author=David Ornstein , title=Arsenal 3 - 0 Bolton , work=BBC Sport citation , page= , passage=Arsenal lacked urgency and inspiration until shortly before half-time, Wheater's block denying Van Persie from close range before Walcott drilled wide.}}