What does Ms Stand for?

Mistress is the female equivelent of Mister. During the 18th century it was common to refer to females as Mistress when their marital status was unknown or irrelevant. Since Mister had been shortened to Mr by using the first and last letter, Mistress was shortened to Ms by using the first and last letter.
Copyright © 2014 Dictionary.com, LLC. All rights reserved.