Where does “40enne” come from?

40enne (Italian) comes from Italian -enne, from Latin -ennis, from Latin annus, from Proto-Italic atnos, from Proto-Indo-European h₂et-no-, from Proto-Indo-European h₂et- — grass.

Ancestry of “40enne”, step by step

Step	Language	Word	Meaning
1	Italian	-enne	-year-old; Also forms similar terms related to...
2	Latin	-ennis	—
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- →