What is finna roast?

Me: Bro your hair be spellin DANK!

Niggah: JIT NOW IM FINNA ROAST! LOOK AT YO UGLY AHH HAIRCUT N YO HIGH SHORTS WIT YOUR SHIRT TUCKED IN AND swag

finna roast - video

Finna roast is when u about roast the shit outta someone

"Boi I finna roast yo ass"