Where does “pluriannuel” come from?

pluriannuel (French) comes from French annuel, from Late Latin annualis, from Latin annus, from Proto-Italic atnos, from Proto-Indo-European h₂et-no-, from Proto-Indo-European h₂et- — grass.

pluriannuel (French): long-term; pluriennial

Definitions

long-term; pluriennial

Ancestry of “pluriannuel”, step by step

Step	Language	Word	Meaning
1	French	annuel	annual, yearly
2	Late Latin	annualis	one-year-old
3	Latin	annus	year; time; season
4	Proto-Italic	atnos	year
5	Proto-Indo-European	h₂et-no-	—
6	Proto-Indo-European	h₂et-	grass

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