(~s)
1.
A ~ is something written at the end of a letter after you have signed your name. You usually write ‘PS’ in front of it.
A brief, hand-written ~ lay beneath his signature.
N-COUNT
2.
A ~ is an addition to a finished story, account, or statement, which gives further information.
I should like to add a ~ to your obituary for John Cage.
N-COUNT: oft N to n