cubitiere vs armor plate

cubitiere and armor plate both are nouns.

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

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

cubitiere: body armor that protects the elbow
armor plate: specially hardened steel plate used to protect fortifications or vehicles from enemy fire

Other hypernyms of cubitiere include armor plating, armour plate, plate armor, plate armour.

cubitiere (noun)	armor plate (noun)
body armor that protects the elbow	specially hardened steel plate used to protect fortifications or vehicles from enemy fire