Derived from the Latin dux, meaning "a leader;" Arabic, "a sheik." This word is used to denote the phylarch or chief of a tribe (Genesis 36:15-43; Exodus 15:15; 1 Chronicles 1:51-54).

Noah Webster's New International Dictionary of the English Language

1. (n.) A leader; a chief; a prince.

2. (n.) In England, one of the highest order of nobility after princes and princesses of the royal blood and the four archbishops of England and Ireland.

3. (n.) In some European countries, a sovereign prince, without the title of king.

4. (v. i.) To play the duke.