Etimoloji
Inherited from Old East Slavic прочии (pročii, “other”). Cognate with Serbo-Croatian про̏чӣ (“other”). Per Vasmer, apparently an original comparative of Proto-Slavic *prokъ (whence Russian прок (prok)), originally an adjective meaning "ahead". See Russian прочь (pročʹ) and прок (prok) for more information.