any of various large ancient Greek coins
"The collector carefully cleaned each medallion, admiring how the ancient Greek coins depicted gods and heroes in such vivid relief."
an emblem indicating that a taxicab is registered
"The driver showed me his shiny gold medallion to prove he was legally allowed to pick up passengers on the street."
an award for winning a championship or commemorating some other event
"The team celebrated by pinning their gold medallion to the captain's jacket after securing the championship title."
A large medal, usually decorative.
"He proudly displayed his silver medallion around his neck at the awards ceremony."
To mark with, or as with, a medallion or medallions.
"The artisan carefully engraved each silver coin to mark it with intricate floral patterns that resembled tiny medallions."