plate armor vs sabaton

plate armor and sabaton both are nouns.

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

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

plate armor: specially hardened steel plate used to protect fortifications or vehicles from enemy fire
sabaton: armor plate that protects the foot; consists of mail with a solid toe and heel

plate armor (noun)	sabaton (noun)
specially hardened steel plate used to protect fortifications or vehicles from enemy fire	armor plate that protects the foot; consists of mail with a solid toe and heel
a historical type of personal armor made from iron or steel plates, which superseded mail during the 14th century.