Where does “ба́рин” come from?

ба́рин (Russian) comes from Russian боя́рин, from Old East Slavic боꙗринъ, from Old Church Slavonic болꙗринъ, from Proto-Slavic bojь, from Proto-Indo-European bʰoyh₂ós, from Proto-Indo-European bʰeyh₂- — to fear, be afraid; to strike, hit; to hew, cut.

ба́рин (Russian): boyar, barin, nobleman, gentleman, landlord a rank of aristocracy in Russia