plate vs armor plating

plate and armor plating both are nouns.

Word	Noun	Adjective	Verb	Adverb
plate	Yes	No	Yes	No
armor plating	Yes	No	No	No

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

plate: a metal sheathing of uniform thickness (such as the shield attached to an artillery piece to protect the gunners)
armor plating: specially hardened steel plate used to protect fortifications or vehicles from enemy fire

Other hyponyms of plate include armor plate, armour plate, plate armor, plate armour, horseshoe, shoe, shell plating.

plate (noun)	armor plating (noun)
dish on which food is served or from which food is eaten	specially hardened steel plate used to protect fortifications or vehicles from enemy fire
a metal sheathing of uniform thickness (such as the shield attached to an artillery piece to protect the gunners)
a sheet of metal or wood or glass or plastic
a shallow receptacle for collection in church
(baseball) base consisting of a rubber slab where the batter stands; it must be touched by a base runner in order to score
structural member consisting of a horizontal beam that provides bearing and anchorage
a full-page illustration (usually on slick paper)
a flat sheet of metal or glass on which a photographic image can be recorded
the positively charged electrode in a vacuum tube
a dental appliance that artificially replaces missing teeth
any flat platelike body structure or part
a main course served on a plate
the thin under portion of the forequarter
a rigid layer of the Earth's crust that is believed to drift slowly
the quantity contained in a plate

plate (verb)	armor plating (verb)
coat with a layer of metal