Parthian shot
addendum
afterthought
appendix
back matter
chorus
coda
codicil
colophon
conclusion
consequence
continuance
continuation
double take
dying words
envoi
epilogue
follow-through
follow-up
last words
parting shot
peroration
postface
postfix
postlude
postscript
refrain
second thought
sequel
sequela
sequelae
sequelant
sequent
sequitur
subscript
suffix
supplement
swan song
tag