Where does “pentennial” come from?

pentennial (English) comes from Latin annus, from Proto-Italic atnos, from Proto-Indo-European h₂et-no-, from Proto-Indo-European h₂et- — grass.

pentennial (English): that occurs every five years

Definitions

  1. that occurs every five years

Ancestry of “pentennial”, step by step

pentennial traces back through two separate lines of ancestry.

via Latin annus

StepLanguageWordMeaning
1Latinannusyear; time; season
2Proto-Italicatnosyear
3Proto-Indo-Europeanh₂et-no-—
4Proto-Indo-Europeanh₂et-grass

via Ancient Greek πέντε

StepLanguageWordMeaning
1Ancient Greekπέντεfive
2Proto-Hellenicpénkʷefive
3Proto-Indo-Europeanpénkʷefive
Every word from Proto-Indo-European h₂et- →Every word from Proto-Indo-European h₂et-no- →Every word from Proto-Italic atnos →