Where does “vīcennālia” come from?

vīcennālia (Latin) comes from Latin vīcennium, from Latin vīcennis, from Latin vīciēs, from Latin annus, from Proto-Italic atnos, from Proto-Indo-European h₂et-no-, from Proto-Indo-European h₂et- — grass.

vīcennālia (Latin): vicennalia, the festival and religious rituals celebrating a Roman emperor's 20th year of rule

Definitions

vicennalia, the festival and religious rituals celebrating a Roman emperor's 20th year of rule

Ancestry of “vīcennālia”, step by step

Step	Language	Word	Meaning
1	Latin	vīcennium	vicennium, a twenty-year period
2	Latin	vīcennis	celebrated or occuring every twenty years, vicennial
3	Latin	vīciēs	twenty times
4	Latin	annus	year; time; season
5	Proto-Italic	atnos	year
6	Proto-Indo-European	h₂et-no-	—
7	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 →