body armor vs suit of armor

body armor and suit of armor both are nouns.

Word	Noun	Adjective	Verb	Adverb
body armor	Yes	No	No	No
suit of armor	Yes	No	No	No

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

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

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

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