Circa (from Latin, meaning 'around, about') - frequently abbreviated c., ca., or ca (and less frequently circ. or cca.) - signifies "approximately" in several European languages (and as a loanword in English), usually in reference to a date.Circa is widely used in historical writing when the dates of events are not accurately known.
When used in date ranges, circa is applied before each approximate date, while dates without circa immediately preceding them are generally assumed to be known with certainty. Thus, a year range like the example below can be expressed with circa in the following ways.