Etymology tree Latin compellō Latin compulsus Proto-Indo-European *-wós Proto-Indo-European *-iHwósder. Latin -īvus Old French -if Middle French -if French -if French compulsifbor. Proto-Indo-European *-nós Proto-Balto-Slavic *-inas Proto-Slavic *-ьnъ Old Polish -ny Polish -ny Polish kompulsywny From French compulsif + Polish -ny.