The full form of Mrs is Missus. It’s used on Academic & Science ,Language & Linguistics in Worldwide

Mrs (Pronounced: missus or missis) is a title that comes before a married woman’s name. Mrs originally stood for “mistress” in the late 15th century. At the time, “mistress” didn’t popularly have the negative connotation it often does today, namely referring to a woman other than a man’s wife who he has an affair with. Today the only accepted full form of Mrs is ‘missus’, one’s wife.