Where does “Polainnis” come from?

Polainnis (Irish) comes from Irish Polainn, from Polish Polanie, from Proto-Slavic poľane, from Proto-Slavic poľe, from Proto-Indo-European pleh₂- — flat.

Ancestry of “Polainnis”, step by step

Step	Language	Word	Meaning
1	Irish	Polainn	Poland
2	Polish	Polanie	Poles; field-dwellers
3	Proto-Slavic	poľane	—
4	Proto-Slavic	poľe	field
5	Proto-Indo-European	pleh₂-	flat

Every word from Proto-Indo-European pleh₂- →

Polainnis — Etymology, Origin & Word History | Etymology Explorer