armor vs suit of armour

armor and suit of armour both are nouns.

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

As nouns, suit of armour is a hyponym of armor; that is, suit of armour is a word with a more specific, narrower meaning than armor:

Other hyponyms of armor include body armor, body armour, cataphract, coat of mail, suit of armor, buckler, shield.

armor (noun)	suit of armour (noun)
tough more-or-less rigid protective covering of an animal or plant	armor that protects the wearer's whole body
protective covering made of metal and used in combat
a military unit consisting of armored fighting vehicles

armor (verb)	suit of armour (verb)
equip with armor