suit of armor vs cataphract

suit of armor and cataphract both are nouns.

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

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

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

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

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