Something added to complete a thing, make up for a deficiency, or extend or strengthen the whole. She takes a vitamin supplement every morning to ensure she gets enough nutrients.
A separate section, especially a magazine or newspaper, that is published in addition to the main publication. The Sunday newspaper comes with a special supplement on travel and leisure.
An additional charge or payment. There is a supplement for single occupancy in the hotel room rates.
In geometry, an angle or arc that when added to a given angle or arc equals 180°. An exterior angle is the supplement of its adjacent interior angle.