noun: (automotive) Acronym of vehicle identification number. [A mandatory unique alphanumeric code (usually 17 characters long) assigned to each vehicle produced, stamped into the metal on the dashboard on the left-hand side (viewable through the windshield), and on the engine block and at least one other place somewhere on the body of the vehicle.]
noun: (medicine) Acronym of vulvar intraepithelial neoplasia.