usage: the quality of prevailing generally; being widespread; "he was surprised by the prevalence of optimism about the future"
2. prevalence, ratio
usage: (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. preponderance, prevalence, number, figure
usage: a superiority in numbers or amount; "a preponderance of evidence against the defendant"