vt to fill up or supply by addition; to add something to.
2. supplement ·vt that which supplies a deficiency, or meets a want; a store; a supply.
3. supplement ·vt the number of degrees which, if added to a specified arc, make it 180°; the quantity by which an arc or an angle falls short of 180 degrees, or an arc falls short of a semicircle.
4. supplement ·vt that which fills up, completes, or makes an addition to, something already organized, arranged, or set apart; specifically, a part added to, or issued as a continuation of, a book or paper, to make good its deficiencies or correct its errors.