coat of mail vs suit of armor

coat of mail and suit of armor both are nouns.

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

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

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

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

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