noun, adverb
BC; BCE; before the Common Era
Used to indicate years before the start of the Gregorian calendar. Often placed after a year number, e.g., 500紀元前 (500 BC).
紀元前500年に、この神殿が建てられた。
This temple was built in 500 BC.
その出来事は紀元前にさかのぼる。
The event dates back to before the Common Era.