The Collaborative International Dictionary of English v.0.48:
Duke \Duke\ (d[=u]k), n. [F. duc, fr. L. dux, ducis, leader,
commander, fr. ducere to lead; akin to AS. te['o]n to draw;
cf. AS. heretoga (here army) an army leader, general, G.
herzog duke. See Tue, and cf. Doge, Duchess, Ducat,
Duct, Adduce, Deduct.]
1. A leader; a chief; a prince. [Obs.]
Hannibal, duke of Carthage. --Sir T.
All were dukes once, who were "duces" -- captains or
leaders of their people. --Trench.
2. 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. In some European countries, a sovereign prince, without
the title of king.
4. pl. The fists; as, put up your dukes. [slang]
Duke's coronet. See Illust. of Coronet.
To dine with Duke Humphrey, to go without dinner. See under