To provide or make a supplement to something.

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.

plural of supplementer

One who supplements something. / A person who takes nutritional supplements.

In a supplemental manner.

Relating to supplementation

A charge added to a per-person occupancy rate that is based on an assumption of double occupancy, as on a cruise ship.

plural of single supplement

(medicine) Any substance, such as a vitamin or mineral, taken as a supplement to food to replace nutrients that would otherwise be missing in a person's diet.

plural of market supplement