pos·ses·sive / pəˈzesiv/ • adj. 1. demanding someone's total attention and love: as soon as she'd been out with a guy a few times, he'd get possessive she was possessive of our eldest son. ∎ showing a desire to own things and an unwillingness to share what one already owns: young children are proud and possessive of their own property.2. Gram. relating to or denoting the case of nouns and pronouns expressing possession.• n. Gram. a possessive word or form. ∎ (the possessive) the possessive case.DERIVATIVES: pos·ses·sive·ly adv.pos·ses·sive·ness n.