An addendum is an extra piece you put on after the main text is already there — at the end of a book, a report, a speech, or, very often, a contract. It adds information, or it changes something, without rewriting the whole thing. In books, people also say appendix or supplement.

An addenduman addendum is an extra piece you put on after the main text is already there是指在正文已經完成之後，額外加上去的一部分 — at the end of a book, a report, a speech, or, very often, a contract通常加在書、報告、演講稿的最後，或者很常見的是合約的最後。It adds information, or it changes something它可能是補充資訊，也可能是改動某個地方, without rewriting the whole thing但不需要把整份東西重寫一遍。In books, people also say appendix or supplement在書裡，大家也會說appendix（附錄）或supplement（增補）。

Addendum often feels like “we needed to add this later,” after the first version had gone out. In legal English it is quite at home: a signed extra page that tweaks the deal. It is a formal, paper word.

Addendumaddendum often feels like 'we needed to add this later,' after the first version had gone out常常給人的感覺是「初版已經發出去之後，才發現需要補這一段」。In legal English it is quite at home在法律英文裡它非常常見: a signed extra page that tweaks the deal就是一份簽了名、用來微調協議內容的額外附頁。It is a formal, paper word這是個正式、書面用的字。

Though actually, almost nobody giving a speech says “I have an addendum.” They say “one more thing” or “let me add.” You meet this word on the page.

Though actually不過事實上, almost nobody giving a speech says 'I have an addendum.'幾乎沒有人演講時會說「I have an addendum」 They say 'one more thing' or 'let me add.'他們會說「one more thing」（還有一件事）或「let me add」（我再補充一下） You meet this word on the page你是在書面文字上才會遇到這個字。

The old Latin plural is addenda, and careful writers still use it; addendums appears too, and some readers wince. One addendum, two addenda is the tidy pattern.

The old Latin plural is addenda古老的拉丁文複數是addenda, and careful writers still use it講究的作者現在還是會這樣用; addendums appears too，addendums這個複數也會出現, and some readers wince不過有些讀者看了會皺眉頭。One addendum, two addendaOne addendum、two addenda is the tidy pattern是比較工整的用法。

It is not a random extra paragraph in the middle; the idea is “stuck on, usually at the end, because the main thing was already done.”

It is not a random extra paragraph in the middle它不是中間隨便插一段的額外文字; the idea is 'stuck on, usually at the end, because the main thing was already done.'它的概念是「因為主要的東西已經做完了，所以貼加在後面，通常是最後」。