# supplement

/ˈsəpɫəmənt/ (US)

Source: https://englishreference.com/word/supplement
Updated: 2026-06-19

## Senses

### 1. dietary additive

noun · CEFR B2

a pill or powder you take to get more vitamins or minerals in your diet.

For teachers: a substance, such as a vitamin or mineral, taken orally to compensate for a nutritional deficiency or to enhance physical performance.

- He takes a daily vitamin supplement to make sure he gets enough iron.
- Athletes often use protein supplements to aid muscle recovery after intense training sessions, though experts recommend a balanced diet first.

### 2. extra document or section

noun · CEFR B2

an extra part of a book, newspaper, or report that gives more information.

For teachers: an additional section or document that provides further information, updates, or corrections to a primary publication.

- The Sunday newspaper comes with a travel supplement full of holiday ideas.
- The technical manual includes a supplement that details the software changes introduced in the latest security patch.

### 3. extra cost

noun · CEFR C1 · Formal

an extra amount of money you pay for a special service or item.

For teachers: an additional charge or surcharge, often applied to travel or dining for premium services.

- There is a small supplement if you want a room with a sea view.
- The tour package price is based on double occupancy, so solo travellers must pay a single-room supplement.

### 4. geometry

noun · CEFR C2 · Technical

the amount of an angle that must be added to another to make 180 degrees.

For teachers: the angle that, when added to a given angle, results in a total of 180 degrees.

- If one angle is 110 degrees, its supplement is 70 degrees.
- Students were asked to calculate the supplement of various obtuse angles to demonstrate their understanding of linear pairs.

### 5. to add to

verb · CEFR B2

to add something to another thing to make it better or more complete.

For teachers: to add an extra element to something so as to enhance or complete it. Transitive; typically takes a direct object.

- She works part-time in the evenings to supplement her student loan.
- The lecturer suggested that students supplement their core reading with academic journals to gain a deeper understanding of the topic.

## Examples

- I take a daily vitamin supplement to stay healthy.
- The Sunday newspaper includes a travel supplement with tips on affordable European vacations.
- The author provided a technical supplement to the main text, offering detailed mathematical proofs that would have otherwise disrupted the narrative flow of the primary chapters.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.