Olympiad vs time period

Olympiad and time period both are nouns.

Word	Noun	Adjective	Verb	Adverb
Olympiad	Yes	No	No	No
time period	Yes	No	No	No

As nouns, time period is a hypernym of Olympiad; that is, time period is a word with a broader meaning than Olympiad:

Olympiad: one of the four-year intervals between Olympic Games; used to reckon time in ancient Greece for twelve centuries beginning in 776 BC
time period: an amount of time

Other hypernyms of Olympiad include period, period of time.

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