addendum addenda • adder · · · Info · Definitions · Synonyms · Characters · · addendum · · Text Latin · · Script 8 · · Length Definitions · · · (noun) textual matter that is added onto a publication; usually at the end. Synonyms: supplement, postscript. · · Noun Definition 1 Synonyms · · · supplement · · Synonym 1 postscript · · Synonym 2 Characters · · a latin small letter a U+0061 d latin small letter d U+0064 e latin small letter e U+0065 m latin small letter m U+006D n latin small letter n U+006E u latin small letter u U+0075