contorniate
A bronze medal or medallion with a deep furrow on the contour or edge, supposed to have been struck in the days of Constantine and his successors.
Mr. Evans exhibited a fine contorniate, bearing the head of Nero
Where it comes from
From Italian contorniato, present participle of contorniare (“to make a circuit or outline”).
Adapted from the Wiktionary entry contorniate (CC BY-SA 4.0).