The term 'Italian Possessive Pronoun' refers to the pronouns used in the Italian language to indicate possession or ownership. The three most common possessive pronouns are 'mio' (3 letters), 'sua' (3 letters) and 'nostro' (6 letters). 'Mio' is used when referring to something that belongs to oneself, 'sua' is used when referring to something that belongs to someone else, and 'nostro' is used when referring to something that belongs to a group of people.