pectoral vs pectoral medallion

pectoral and pectoral medallion both are nouns.

Word	Noun	Adjective	Verb	Adverb
pectoral	Yes	Yes	No	No
pectoral medallion	Yes	No	No	No

As nouns, pectoral and pectoral medallion are synonyms defined as:

pectoral and pectoral medallion: an adornment worn on the chest or breast

pectoral (noun)	pectoral medallion (noun)
an adornment worn on the chest or breast	an adornment worn on the chest or breast
either of two large muscles of the chest

pectoral (adjective)	pectoral medallion (adjective)
of or relating to the chest or thorax