Definitions for olympiadəˈlɪm piˌæd, oʊˈlɪm-
Random House Webster's College Dictionary
O•lym•pi•ad*əˈlɪm piˌæd, oʊˈlɪm-(n.)
a period of four years reckoned from one celebration of the Olympic Games to the next, by which the Greeks computed time from 776 b .c .
a celebration of the modern Olympic Games.
Ref: Olympic Games (def. 2). 2
* (often l.c.).
Origin of Olympiad:
1350–1400; ME < L Olympias < Gk Olympiás. See Olympia , -ad1
one of the four-year intervals between Olympic Games; used to reckon time in ancient Greece for twelve centuries beginning in 776 BC
Olympic Games, Olympics, Olympiad(noun)
the modern revival of the ancient games held once every 4 years in a selected country
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 b.c.; as, the era of the olympiads.
The Nuttall Encyclopedia
a name given to the period of four years between one celebration of the Olympic Games and another, the first recorded dating from July 776 B.C.