As a noun frequency
is (uncountable) the rate of occurrence of anything; the relationship between incidence and time period.
As a adjective subsonic is
(of a sound) having a frequency too low to be audible.
Other Comparisons: What's the difference?
(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 a periodic phenomenon occurs over the time in which it occurs: .
* The frequency of the musical note A above middle C is 440 oscillations per second.
* ''The frequency of a wave is its velocity divided by its wavelength : .
* 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)
* (rate of occurrence) oftenness
* (rate of occurrence) period
(of a sound) having a frequency too low to be audible
(of a speed) less than the speed of sound (in the same medium, and at the same temperature and pressure)
(fluid mechanics, of a flow) with a Mach number such that 0.3 < Ma < 0.8 (approximately - the exact limits vary between sources).