Where does “забросать” come from?

забросать (Russian) comes from Russian броса́ть, from Proto-Slavic brъsati, from Proto-Balto-Slavic bruśetei, from Proto-Indo-European bʰruḱ-.

Ancestry of “забросать”, step by step

Step	Language	Word	Meaning
1	Russian	броса́ть	—
2	Proto-Slavic	brъsati	to wipe
3	Proto-Balto-Slavic	bruśetei	—
4	Proto-Indo-European	bʰruḱ-	—

забросать — Etymology, Origin & Word History | Etymology Explorer