A period of four years, by which the ancient Greeks reckoned time, being the interval from one celebration of the Olympic games to another, beginning with the victory of Corbus in the foot race, which took place in the year 776 BC; as, the era of the olympiads.
User Defined Definitions
"one of the four-year intervals between Olympic Games; used to reckon time in ancient Greece for twelve centuries beginning in 776 BC"
"the modern revival of the ancient games held once every 4 years in a selected country"