circa
prep.prep. around or approximately. You use this before a date or a number when you do not know the exact time or amount.
prep. approximately or about; used primarily with dates or numerical figures to indicate an estimated point in time. Often abbreviated as 'c.' or 'ca.' in academic writing.
The old church was built circa 1450.
The museum curator estimated that the bronze statue was cast circa 300 BC, though the exact decade remains unknown.
While the manuscript is undated, linguistic evidence suggests it was composed circa the late twelfth century, during a period of significant transition in the local dialect.
Typically precedes a specific year, century, or era. In formal or academic contexts, it is frequently abbreviated to 'c.' or 'ca.' followed by a space.