The Collaborative International Dictionary of English v.0.48:

Dine \Dine\, v. i. [imp. & p. p. Dined; p. pr. & vb. n.
   Dining.] [F. d[^i]ner, OF. disner, LL. disnare, contr. fr.
   an assumed disjunare; dis- + an assumed junare (OF. juner) to
   fast, for L. jejunare, fr. jejunus fasting. See Jejune, and
   cf. Dinner, D?jeuner.]
   To eat the principal regular meal of the day; to take dinner.
   [1913 Webster]

         Now can I break my fast, dine, sup, and sleep. --Shak.
   [1913 Webster]

   To dine with Duke Humphrey, to go without dinner; -- a
      phrase common in Elizabethan literature, said to be from
      the practice of the poor gentry, who beguiled the dinner
      hour by a promenade near the tomb of Humphrey, Duke of
      Gloucester, in Old Saint Paul's.
      [1913 Webster]

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.]
      [1913 Webster]

            Hannibal, duke of Carthage.           --Sir T.
                                                  Elyot.
      [1913 Webster]

            All were dukes once, who were "duces" -- captains or
            leaders of their people.              --Trench.
      [1913 Webster]

   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.
      [1913 Webster]

   3. In some European countries, a sovereign prince, without
      the title of king.
      [1913 Webster]

   4. pl. The fists; as, put up your dukes. [slang]
      [PJC]

   Duke's coronet. See Illust. of Coronet.

   To dine with Duke Humphrey, to go without dinner. See under
      Dine.
      [1913 Webster]