Where does “алень” come from?

алень (Belarusian) comes from Proto-Slavic (j)elenь, from Proto-Indo-European h₁el-en-i-.

алень (Belarusian): deer

Definitions

Step	Language	Word	Meaning
1	Proto-Slavic	(j)elenь	—
2	Proto-Indo-European	h₁el-en-i-	—

алень — Etymology, Origin & Word History | Etymology Explorer