Source : Webster's Revised Unabridged Dictionary (1913)

Madonna \Ma*don"na\, n. [It. madonna my lady. See {Dame},
   {Donna}, and cf. {Madame}, {Monkey}.]
   1. My lady; -- a term of address in Italian formerly used as
      the equivalent of Madame, but for which Signora is now
      substituted. Sometimes introduced into English. --Shak.

   2. [pl. {Madonnas} (n[.a]z).] A picture of the Virgin Mary
      (usually with the babe).

            The Italian painters are noted for drawing the
            Madonnas by their own wives or mistresses. --Rymer.

Source : WordNet®

Madonna
     n 1: the mother of Jesus; Christians refer to her as the Virgin
          Mary; she is especially honored by Roman Catholics [syn:
           {Mary}, {Virgin Mary}, {The Virgin}, {Blessed Virgin}]
     2: United States pop singer and sex symbol during the 1980s
        (born in 1958) [syn: {Madonna Louise Ciccone}]