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1. The quality of prevailing generally; being widespread
   "he was surprised by the prevalence of optimism about the future"
    
2. (epidemiology) the ratio (for a given time period) of the number of occurrences of a disease or event to the number of units at risk in the population
    
3. A superiority in numbers or amount
   - preponderance

Derived forms: prevalences

See also: prevail, prevalent

Type of: figure, generality, number, ratio

Encyclopedia: Prevalence