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.

An additional section of a newspaper devoted to a specific subject.

An angle that, when added to a given angle, makes 180°; a supplementary angle.

(nutrition) A vitamin, herbal extract or chemical compound ingested to meet dietary deficiencies or enhance muscular development.

An additional charge, especially for food in a restaurant.

“There is a £2 supplement if you choose the steak.”

To provide or make a supplement to something.