supplement
Something added, especially to make up for a deficiency.
An extension to a document or publication that adds information, corrects errors or brings up to date.
(journalism) An additional section of a newspaper devoted to a specific subject.
(geometry) An angle that, when added to a given angle, makes 180°; a supplementary angle.
(nutrition, bodybuilding) A vitamin, herbal extract or chemical compound ingested to meet dietary deficiencies or enhance muscular development.
A surcharge, additional cost, especially for food in a restaurant.
To provide or make a supplement to something.