used instead of Mrs or Miss, esp when the woman's marital status is unknown or irrelevant
Ms, Mrs, or Miss? Traditionally, the title Miss was used by a woman before marriage together with her maiden name, while Mrs was used after marriage together with her husband's surname: Miss Jones became Mrs Smith when she married. From the 1950s onwards, the title Ms began to be used by women who did not wish to disclose their marital status, thought it irrelevant, or felt an all-purpose title for women equivalent to Mr was needed. This title was also used by some people when writing to or addressing women whose marital status was unknown: it is very useful for this purpose. Ms is gradually acquiring wider acceptance, especially among younger people. Some people, however, dislike its associations with feminism and insist on using or being addressed by the traditional titles