postscript has definitions from the field of writing
1
[ noun ] (writing) a note appended to a letter after the signature

Synonyms

PS

Used in print

(John Dos Passos, Midcentury....)

She added a postscript begging me to be careful about drinking .

Related terms

note letter

2
[ noun ] (writing) textual matter that is added onto a publication; usually at the end

Synonyms

supplement addendum

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