ˈpōs(t)ˌskript noun
Etymology: New Latin postscriptum, from Latin, neuter of postscriptus, past participle of postscribere to write after, from post- + scribere to write — more at scribe
: a note or series of notes appended to a completed composition (as a letter, article, or book) usually giving an afterthought or additional information
added a postscript to the … manuscript — R.H.Gabriel
included in the autobiography as a sort of postscript — Harper's
— abbr. PS, ps