coat of mail vs body armor

coat of mail and body armor both are nouns.

Word	Noun	Adjective	Verb	Adverb
coat of mail	Yes	No	No	No
body armor	Yes	No	No	No

As nouns, coat of mail and body armor are synonyms defined as:

coat of mail and body armor: armor that protects the wearer's whole body

Other synonyms of coat of mail include body armour, cataphract, suit of armor, suit of armour.

coat of mail (noun)	body armor (noun)
armor that protects the wearer's whole body	armor that protects the wearer's whole body