armor plate vs armour plate

armor plate and armour plate both are nouns.

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

As nouns, armor plate and armour plate are synonyms defined as:

armor plate and armour plate: specially hardened steel plate used to protect fortifications or vehicles from enemy fire

Other synonyms of armor plate include armor plating, plate armor, plate armour.

armor plate (noun)	armour plate (noun)
specially hardened steel plate used to protect fortifications or vehicles from enemy fire	specially hardened steel plate used to protect fortifications or vehicles from enemy fire