Where does “Śliwa” come from?

Śliwa (Polish) comes from Polish śliwa, from Proto-Slavic sliva, from Proto-Balto-Slavic *slīˀwā́ˀ, from Proto-Indo-European (s)leh₃y- — blueish.

Ancestry of “Śliwa”, step by step

Step	Language	Word	Meaning
1	Polish	śliwa	plum
2	Proto-Slavic	sliva	plum; plum tree
3	Proto-Balto-Slavic	*slīˀwā́ˀ	—
4	Proto-Indo-European	(s)leh₃y-	blueish

Śliwa — Etymology, Origin & Word History | Etymology Explorer