Definition of: madam

(mad′əm) noun plural mes·dames (mā·däm′, Fr. mā·dám′) for def.
1; mad·ams for def. 2.
1. My lady; mistress: a title of courtesy originally addressed to a woman of rank or high position, but now used to any woman, as at the beginning of a letter. Compare SIR. See MA'AM.
2. The mistress of a brothel. [<OF ma dame <ma my (<L meus) + dame lady <L domina. Doublet of MADONNA, MADAME.]