Enter a clue or pattern or both:
The Clue
Supplement (8 letter answer)
The Answer
ADDENDUM
Tags
Notes
The answer ADDENDUM is so rare that it appears less than once every 2500 puzzles.
Related Clues
Postscript
Definition
ADDENDUM as a noun:
1. (addendum, supplement, postscript) = textual matter that is added onto a publication; usually at the end