Essentially a variation of the Southern term "Fixin' to", which basically means that you are (planning to/ compelled to) do something or go somewhere.
I'm finna get some plutonium today.
She's finna start some trouble with Bret!
He's finna go down to the store and get some mint milano cookies.
She's finna start some trouble with Bret!
He's finna go down to the store and get some mint milano cookies.
by Travon0jackson April 22, 2020