Where does “Pologna” come from?

Pologna (Romansch) comes from Latin Polonia, from Proto-Slavic poľane, from Proto-Slavic poľe, from Proto-Indo-European pleh₂- — flat.

Ancestry of “Pologna”, step by step

Step	Language	Word	Meaning
1	Latin	Polonia	Poland
2	Proto-Slavic	poľane	—
3	Proto-Slavic	poľe	field
4	Proto-Indo-European	pleh₂-	flat

Pologna — Etymology, Origin & Word History | Etymology Explorer