olympiad
noun
olym·pi·ad ə-ˈlim-pē-ˌad 
ō-
often capitalized
1
: one of the 4-year intervals between Olympic Games by which time was reckoned in ancient Greece
2
: a quadrennial celebration of the modern Olympic Games
also : a competition or series of competitions resembling an olympiad especially in variety or challenge
Example Sentences
Recent Examples on the Web That's when Sneha Mohan and Michael Kim, who now recently finished up the eighth grade, and other Science Olympiads at Daniel Wright, presented the coaches with an offer. 
Ronnie Wachter, chicagotribune.com, 9 June 2017 But a calling is a calling, and Ms. Benton answered hers, entering scholarship competitions and arts Olympiads until she was accepted into the acting conservatory at Carnegie Mellon. Alexis Soloski, New York Times, 11 May 2017
Ronnie Wachter, chicagotribune.com, 9 June 2017 But a calling is a calling, and Ms. Benton answered hers, entering scholarship competitions and arts Olympiads until she was accepted into the acting conservatory at Carnegie Mellon. Alexis Soloski, New York Times, 11 May 2017 Word History
Etymology
Middle English Olympias, from Latin Olympiad-, Olympias, from Greek, from Olympia, site of ancient Olympic Games
First Known Use
14th century, in the meaning defined at sense 1