Medallion

google

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mid 17th century: from French médaillon, from Italian medaglione, augmentative of medaglia (see medal).

wiktionary

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Borrowed from French médaillon

etymonline

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medallion (n.)

"a large medal," also applied to anything shaped like one, 1650s, from French médaillon (17c.), from Italian medaglione "large medal," augmentative of medaglia (see medal (n.)).