tri·​en·​ni·​um trī-ˈe-nē-əm How to pronounce triennium (audio)
plural trienniums or triennia trī-ˈe-nē-ə How to pronounce triennium (audio)
: a period of three years

Word History


Latin, from tri- + annus year — more at annual

First Known Use

1847, in the meaning defined above

Time Traveler
The first known use of triennium was in 1847

Dictionary Entries Near triennium

Cite this Entry

“Triennium.” Dictionary, Merriam-Webster, Accessed 4 Oct. 2023.

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