Where does “господинъ” come from?
господинъ (Old Church Slavonic) comes from Proto-Slavic gospodinъ, from Proto-Slavic gospodь, from Proto-Balto-Slavic gastipatis, from Proto-Indo-European gʰóstipotis, from Proto-Indo-European pótis, from Proto-Indo-European ph₃tis, from Proto-Indo-European peh₃- — to drink.
господинъ (Old Church Slavonic): lord; master
Ancestry of “господинъ”, step by step