noun

• (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 a periodic phenomenon occurs over the time t in which it occurs: f=n/t.
• A tone, character, mood, or vibe
• (statistics) number of times an event occurred in an experiment (absolute frequency)