Synonyms of addendum

addendum

noun

ə-ˈden-dəm 

1

as in appendix

a part added at the end of a book or periodical

there's an addendum from the author to explain certain stylistic choices that she made

Synonyms & Similar Words

• appendix
• codicil
• afterword
• supplement
• epilogue
• documentation
• conclusion
• addition
• postscript
• coda
• sequel
• excursus
• accompaniment
• finale
• ending
• follow-up
• complement
• postlude
• rider
• allonge

Antonyms & Near Antonyms

• introduction
• preface
• foreword
• prologue

2

as in increase

something added (as by growth)

with each new addendum the list of demands simply got more absurd

Synonyms & Similar Words

• increase
• addition
• boost
• gain
• rise
• supplement
• increment
• raise
• accrual
• augmentation
• expansion
• uptick
• accretion
• proliferation
• plus
• step-up
• continuation
• accumulation
• appendix
• extension
• more
• collection
• complement
• assemblage
• gathering
• spike
• jump
• upturn
• accession
• uptrend
• run-up

Antonyms & Near Antonyms

• reduction
• decrease
• loss
• diminution
• decline
• abatement
• lowering
• depletion
• fall
• shrinkage
• decrement
• lessening
• deduction
• step-down
• diminishment
• subtraction
• falloff
• drop-off

Example Sentences

Recent Examples of addendum

Lawyers at the Office of Policy and Strategy were frequently told to remove their findings from the main text of agency documents and include them as an addendum. —Jonathan Blitzer, New Yorker, 17 Feb. 2026

Republicans framed the bathroom and driver’s license bill as an addendum clarifying the intent of a separate 2023 bill barring trans women from accessing female-only spaces. —Matthew Kelly, Kansas City Star, 13 Feb. 2026

The lease addendums are a mandatory part of rental agreements across Arizona and the nation. —AZCentral.com, 4 Feb. 2026

The show is light on tech, but the accompanying images (video design by Stefano DeCarli) pour through as addendums to Felder’s puissant passion of Liszt’s Liebesträume or Beethoven’s Für Elise and land with great effect. —David John Chávez, Mercury News, 30 Jan. 2026