supplement

1 of 2

noun

sup·​ple·​ment ˈsə-plə-mənt 

1

a

: something that completes or makes an addition

b

: dietary supplement

2

: a part added to or issued as a continuation of a book or periodical to correct errors or make additions

3

: an angle or arc that when added to a given angle or arc equals 180°

supplement

2 of 2

verb

sup·​ple·​ment ˈsə-plə-ˌment 

supplemented; supplementing; supplements

transitive verb

: to add or serve as a supplement to

does odd jobs to supplement his income

supplementation

ˌsə-plə-ˌmen-ˈtā-shən 

-mən-

noun

supplementer

ˈsə-plə-ˌmen-tər 

noun

Synonyms of supplement

Noun

• increase
• boost
• addition
• gain

Examples of supplement in a Sentence

Noun

the supplement to the encyclopedia

First-class accommodation is available for a supplement.

Verb

She began supplementing her diet with vitamins.

Recent Examples on the Web

Noun

This growth is driven by increasing demand for natural food colors, color-changing beverages, health supplements, and organic skin care products. — Encyclopedia Britannica, 9 Oct. 2026

The development comes after Klitschko, a former boxer, filed a supplement this week to his September guardianship petition, claiming a non-family member had sold some of Panettiere's possessions, including jewelry, to a pawn shop. — ABC News, 9 Oct. 2026

Verb

The ampd fan research, conducted online in Indonesia, Japan, Korea, the Philippines, Thailand and Australia and supplemented by 1,029 video interviews, found that personal connections are the most common route into a sport for new fans. — Naman Ramachandran, Variety, 9 Oct. 2026

According to the letter, Skolnick was fired largely due to his decision to supplement his salary at the CAC — which this year reached $75,000 — by working as a freelance film booker for other indie cinemas. — Adam B. Vary, IndieWire, 9 Oct. 2026

Word History

Etymology

Noun

Middle English, borrowed from Anglo-French & Latin; Anglo-French, borrowed from Latin supplēmentum "something added to supply a deficiency or make up a whole, reinforcement," from supplēre "to fill up, complete, raise to its full complement" + -mentum -ment — more at supply entry 2

Verb

derivative of supplement entry 1

First Known Use

Noun

14th century, in the meaning defined at sense 1a

Verb

1659, in the meaning defined above

Phrases Containing supplement

• colour supplement
• dietary supplement

Kids Definition

supplement

1 of 2 noun

sup·​ple·​ment ˈsəp-lə-mənt 

1

: something that supplies what is needed or makes an addition

vitamin pills used as dietary supplements

2

: an arc or angle that when added to a given arc or angle equals 180 degrees

supplemental

ˌsəp-lə-ˈment-ᵊl

adjective

supplement

2 of 2 verb

sup·​ple·​ment ˈsəp-lə-ˌment 

: to add to

supplement their incomes by doing odd jobs

supplementation

ˌsəp-lə-ˌmen-ˈtā-shən 

-mən-

noun

Medical Definition

supplement

1 of 2 noun

sup·​ple·​ment ˈsəp-lə-mənt 

1

: something that completes or makes an addition

2

: dietary supplement

supplement

2 of 2 transitive verb

sup·​ple·​ment ˈsəp-lə-ˌment 

: to add a supplement to : serve as a supplement for

utilizes … surgery to supplement the traditional treatment

—Therapeutic Notes

supplementation

ˌsəp-lə-ˌmen-ˈtā-shən, -mən- 

noun