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.
2. 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)
Origin: It. Madonna my lady. See dame, Donna, and cf. Madame, monkey.