Difference between Archduke and Duke

Archduke

Part of speech: noun

Definition: The son or male-line grandson of an emperor of the Austro-Hungarian Empire.

Duke

Part of speech: noun

Definition: The male ruler of a duchy (compare duchess).A high title of nobility; the male holder of a dukedom.A grand duke.A fist.

Part of speech: verb

Definition: To hit or beat with the fists

Example sentence: I never have really become accustomed to the 'John.' Nobody ever really calls me John... I've always been Duke or Marion or John Wayne. It's a name that goes well together, and it's like one word - John Wayne.