Triennial describes something that happens once every three years — a triennial meeting, a triennial report, a triennial art show. It can also describe something that lasts three years, as in a triennial term of office, though the 'every three years' meaning is far more common and is what students will meet.

Triennial describes something that happens once every three yearsTriennial用來形容每三年發生一次的事—— a triennial meeting, a triennial report, a triennial art showtriennial meeting（三年一次的會議）、triennial report（三年一次的報告）、triennial art show（三年一次的藝術展）。 It can also describe something that lasts three years它也可以形容持續三年的事， as in a triennial term of office像triennial term of office（為期三年的任期）， though the 'every three years' meaning is far more common and is what students will meet不過『每三年一次』這個意思常見得多，也是學生會遇到的意思。

It is a formal word, at home in official notices, company rules and academic writing; in normal speech people simply say 'every three years', which is clearer and always safe. It is also a noun: 'a triennial' is the event itself, and in the art world some big international exhibitions are called Triennials, alongside the more famous Biennials held every two years.

It is a formal word, at home in official notices, company rules and academic writing這是一個正式的字，用在官方公告、公司規定和學術寫作裡很自然； in normal speech people simply say 'every three years', which is clearer and always safe平常講話大家就直接說『every three years（每三年）』，比較清楚，也永遠不會出錯。 It is also a noun它也可以當名詞： 'a triennial' is the event itself『a triennial』就是那個活動本身， and in the art world some big international exhibitions are called Triennials在藝術界，有些大型國際展覽就叫做Triennial， alongside the more famous Biennials held every two years跟每兩年舉辦一次、更有名的Biennial並列。