Where does “triennial” come from?

Triennial derives from Latin triennium, a period of three years, from Latin annus (year) combined with the numeral three, which traces back through Proto-Germanic þrīz to Proto-Indo-European tréyes.

triennial (English): Happening every three years; Lasting for three...

Definitions

  1. Happening every three years; Lasting for three...

Ancestry of “triennial”, step by step

StepLanguageWordMeaning
1Latintrienniuma period of three years, triennium
2Latintriennisthree-year-old
3Latinannusyear; time; season
4Proto-Italicatnosyear
5Proto-Indo-Europeanh₂et-no-—
6Proto-Indo-Europeanh₂et-grass

Words derived from “triennial”

Every word from Proto-Indo-European h₂et- →Every word from Proto-Indo-European h₂et-no- →Every word from Proto-Italic atnos →