Where does “пјешчаник” come from?

пјешчаник (Serbo-Croatian) comes from Serbo-Croatian пије́сак, from Proto-Slavic pěsъkъ, from Proto-Indo-European pē(n)s-u-ko-.

пјешчаник (Serbo-Croatian): sandstone

Definitions

Step	Language	Word	Meaning
1	Serbo-Croatian	пије́сак	—
2	Proto-Slavic	pěsъkъ	sand
3	Proto-Indo-European	pē(n)s-u-ko-	—

пјешчаник — Etymology, Origin & Word History | Etymology Explorer