Synonyms of the word

addendum

• n. Something to be added; especially text added as an appendix or supplement to a document.
• n. A postscript.
• n. (engineering) The height by which the tooth of a gear projects beyond (outside for external, or inside…

matter

• n. Substance, material.
• n. A condition, subject or affair, especially one of concern.
• n. An approximate amount or extent.
• n. (obsolete) The essence; the pith; the embodiment.
• n. (obsolete) Inducing cause or reason, especially of anything disagreeable or distressing.
• n. (dated) Pus.
• v. (intransitive) To be important.
• v. (transitive, obsolete outside dialects) To care about, to mind; to find important.
• v. To form pus or matter, as an abscess; to maturate.

postscript

• n. (countable) An addendum to a letter, added after the author’s signature.
• n. (countable) An addition to a story, play, etc.
• v. To extend (a letter or another document) with additional remarks.

supplement

• n. Something added, especially to make up for a deficiency.
• n. An extension to a document or publication that adds information, corrects errors or brings up to date.
• n. An additional section of a newspaper devoted to a specific subject.
• n. (geometry) An angle that, when added to a given angle, makes 180°; a supplementary angle.
• n. (nutrition, bodybuilding) A vitamin, herbal extract or chemical compound ingested to meet dietary deficiencies…
• v. To provide or make a supplement to something.