Where does “piastre” come from?

piastre (French) comes from Italian piastra, from Italian impiastrare, from Latin emplastrare.

piastre (French): piastre; buck, dollar

Definitions

Step	Language	Word	Meaning
1	Italian	piastra	sheet, plate; slab; hotplate
2	Italian	impiastrare	to plaster, dirty or smear
3	Latin	emplastrare	—

piastre — Etymology, Origin & Word History | Etymology Explorer