Answer: addendum

AnswerCrossword Clue
ADDENDUMSupplement
ADDENDUMSupplement to a book
ADDENDUMPostscript, e.g.
ADDENDUMBook appendix
ADDENDUMPostscript, say
ADDENDUMMemo p.s.
ADDENDUMCodicil
ADDENDUMSupplement to a book.
ADDENDUMSomething extra.
ADDENDUMSupplement.
ADDENDUMPostscript
ADDENDUMTack-on
addenduma thing added addition
addendumsomething added
addendumsupplement to a book often used in plural but singular in construction