Where does “судья́” come from?

судья́ (Russian) comes from Proto-Slavic sǫdì, from Proto-Indo-European som-dʰh₁-ih₁.

Ancestry of “судья́”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	sǫdì	judge
2	Proto-Indo-European	som-dʰh₁-ih₁	—

судья́ — Etymology, Origin & Word History | Etymology Explorer