The story
- Latin · borrowed fromdecennium
- English todaydecennium
From Latin decennium, from decennis (“10-year”) + -ium (suffix forming abstract nouns), from deciēs (“ten times”) + annus (“year”) + -is (suffix forming compound adjectives). Equivalent to decennial + -ium.
Etymology from Wiktionary, CC BY-SA 4.0.