Circa (often abbreviated c., ca., ca or cca. and sometimes italicized to show it's Latin) means "in approximately" (it literally means "around"), generally referring to a date. It's widely used in genealogy and historical writing, when the dates of events are approximately known. When used in date ranges, a circa's applied before each approximate date, while dates without a circa immediately preceding them are generally assumed to be known with certainty. For example, an encyclopedia entry for… (More on Circa)