shield vs armor

shield and armor both are nouns.

Word	Noun	Adjective	Verb	Adverb
shield	Yes	No	Yes	No
armor	Yes	No	Yes	No

As nouns, armor is a hypernym of shield; that is, armor is a word with a broader meaning than shield:

Other hypernyms of shield include armour.

shield (noun)	armor (noun)
hard outer covering or case of certain organisms such as arthropods and turtles	tough more-or-less rigid protective covering of an animal or plant
armor carried on the arm to intercept blows	protective covering made of metal and used in combat
a protective covering or structure	a military unit consisting of armored fighting vehicles

shield (verb)	armor (verb)
protect, hide, or conceal from danger or harm	equip with armor
hold back a thought or feeling about