coat of mail vs suit of armour

coat of mail and suit of armour both are nouns.

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

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

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

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

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