1. (

• prevalence

) the quality of prevailing generally; being widespread; "he was surprised by the prevalence of optimism about the future" ;

2. (

• prevalence

) (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 ,

) a superiority in numbers or amount; "a preponderance of evidence against the defendant" ;