here is a bit of weirdness

The title Mrs, referring to a married woman, is pronounced as mis' iz, but that is just a traditional slurring of the word mistress which is what Mrs is really an abbreviation for. But the title Miss, meaning an unmarried woman, is also an abbreviation for mistress. It gets even stranger though: many women now prefer to use the title Ms which leaves undisclosed whether the person is married or not. Oddly, it too is an abbreviation for mistress.

The craziness of gender politics. :)