IPA: //traɪˈɛn.i.əm//
KK: /trɪˈɛn.i.əm/
A time span that lasts for three years.
The project will be evaluated at the end of the triennium.
Triennium → It is formed from "tri-" (meaning three) and "annus" (meaning year). The word "triennium" refers to a period of three years.
Think of 'tri-' meaning three and 'annus' meaning year — so a triennium is a span of three years.