(uncountable or countable) The rate of occurrence of anything; the relationship between incidence and time period.

(uncountable) The property of occurring often rather than infrequently.

(countable) The quotient of the number of times n {\displaystyle n} a periodic phenomenon occurs over the time t {\displaystyle t} in which it occurs: f = n / t {\displaystyle f=n/t} .

A tone, character, mood, or vibe

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