Grammar. 1  Also called objective case. (in English and some other languages) a case specialized for the use of a form as the object of a transitive verb or of a preposition, as him in The boy hit him, or me in He comes to me with his troubles. 2  a word in that case.
pinning-a mutual promise of a couple not to date anyone else; on college campuses it was once signaled by the giving of a fraternity pin. promise-a verbal commitment by one person to another agreeing to do (or not to do) something in the future.
pin. 1  a small, slender, often pointed piece of wood, metal, etc., used to fasten, support, or attach things. 2  a short, slender piece of wire with a point at one end and a head at the other, for fastening things together. any of various forms of fasteners or ornaments consisting essentially or partly of a pointed or penetrating wire or shaft (often used in combination): a jeweled pin.