What does supplementary mean?
Supplementary means additional to the main or primary information, material, or purpose. It is commonly used before words such as “information,” “details,” “materials,” “questions,” and “funding,” indicating that the thing being mentioned completes or adds to something already central. The adjective is widely used in formal British and American English, including academic writing, government reports, examinations, and public announcements. As a noun, a supplementary is an extra item or section, such as a supplementary document or payment, although this use is less common. The word often conveys a deliberate secondary addition rather than something that is itself of primary importance. Although “supplemental” is particularly frequent in American usage, “supplementary” is standard in both major varieties of English. Understanding the word is useful because it clearly distinguishes supporting material from the central information or resource.
Additional to the main or primary information, material, or purpose.
"The agency published supplementary guidance for applicants."
Common in formal contexts, especially in education, government, research, and publishing.
An additional item, section, or body of information that adds to something already provided.
"The publisher issued a separate supplementary containing corrections and references."
Less frequent than the adjective and usually used for a distinct supplementary publication, section, payment, or examination paper.
Used for additional documents, sections, payments, or examination papers.
"The committee distributed two supplementaries before the meeting."
A supplementary detail may seem like a minor addition, but it is exactly the kind of extra information that can complete the picture.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does supplementary come from?
The word comes through Old French from the Latin supplementum, meaning “a supply” or “something added,” which was derived from supplere, “to fill up” or “supply.” The adjective entered English in the early 19th century in the sense of serving as an addition. It is related to supplement and supplementation, while supple preserves a separate English use of the same Latin root.
Related word forms
How supplementary is actually used
The adjective is formal and especially common in academic, governmental, and technical contexts. The noun is less frequent and is most natural when referring to an additional document, section, payment, or publication.
Easily confused with supplementary
Both words mean additional; “supplementary” is especially common in British English, while “supplemental” is particularly common in American English.