plectrum (n.)

small instrument used to pluck the strings of a lyre or other stringed musical instrument, late 14c., from Latin plectrum (plural plectra), from Greek plēktron "thing to strike with" (pick for a lyre, cock's spur, spear point, etc.), from plēk-, root of plēssein "to strike" (from PIE root *plak- (2) "to strike").