Generally redundant improvised or unrehearsed lines that are frequently used in rap music.
examples of Ad-libs:
Lil Jon: Whaat? Okay! Yeaah!
Young Jeezy: Daaayum! Ayyyy! Thaaat's Riight!
Hack writing at its purest form.
With Ad-Libs, idiots can now make their own stupid book just by filling in the blanks.