One who attempts to make another's life better against the will of the other. Oversimplified: one who meddles in another business, a busybody. Philosophically: one who considers his own intellect to encompass and exceed the intellect of another, thereby giving him the right and duty to control the life of another, for the other's own good.
My mom remained a gobermouch, always knowing what's best and tricking me into doing it, even after I turned 18.
Under educated neo-nazi type who feels he (or she) is superior to others of different races or ethnic groups based on a misapplied and shaky grasp of the philosophy of Nietzsche.