sup·ple·ment • n. / ˈsəpləmənt/ 1. something that completes or enhances something else when added to it: the handout is a supplement to the official manual. ∎  a substance taken to remedy the deficiencies in a person's diet: multivitamin supplements. ∎  a part added to a book to provide further or corrected information but separate from the main body of the text. ∎  a separate section, esp. a color magazine, added to a newspaper or periodical.2. Geom. the amount by which an angle is less than 180°.• v. / ˈsəpləˌment; -mənt/ [tr.] add an extra element or amount to: she took the job to supplement her husband's income.DERIVATIVES: sup·ple·men·tal / ˌsəpləˈmentl/ adj.sup·ple·men·tal·ly / ˌsəpləˈmentl-ē/ adv.sup·ple·men·ta·tion / ˌsəpləˌmenˈtāshən/ n.

supplement XIV. — L. supplēmentum, f. supplēre SUPPLY; see -MENT.