Olympiad

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An interval of four years between celebrations of the Olympic Games, by which the ancient Greeks reckoned dates.
• noun Sports A celebration of the modern Olympic Games.

from The Century Dictionary.

• noun A period of four years reckoned from one celebration of the Olympic games to another, by which the Greeks computed time from 776 b. c., the reputed first year of the first Olympiad.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Greek Antiq.) 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 Corœbus in the foot race, which took place in the year 776 b. c..
• noun The quadrennial celebration of the modern Olympic games. See Olympics.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun historical 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.
• noun An occurrence of the Olympic games.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the modern revival of the ancient games held once every 4 years in a selected country
• noun one of the four-year intervals between Olympic Games; used to reckon time in ancient Greece for twelve centuries beginning in 776 BC