cubitiere vs armour plate

cubitiere and armour plate both are nouns.

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

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

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

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

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