margrave vs nobleman

margrave and nobleman both are nouns.

Word	Noun	Adjective	Verb	Adverb
margrave	Yes	No	No	No
nobleman	Yes	No	No	No

As nouns, nobleman is a hypernym of margrave; that is, nobleman is a word with a broader meaning than margrave:

margrave: a German nobleman ranking above a count (corresponding in rank to a British marquess)
nobleman: a titled peer of the realm

Other hypernyms of margrave include Lord, noble.

margrave (noun)	nobleman (noun)
a German nobleman ranking above a count (corresponding in rank to a British marquess)	a titled peer of the realm
the military governor of a frontier province in medieval Germany