чрез- (Russian) comes from Russian чрез, from Old Church Slavonic чрѣсъ, from Proto-Slavic čerzъ, from Proto-Balto-Slavic (s)kerso-, from Proto-Indo-European (s)kert-, from Proto-Indo-European (s)ḱer- — dung, manure, filth; manure, dung, filth.
чрез- (Russian): over-, trans-