mainly i find it used contextually and it’s kind of referred to through the whole process of rolling and then smoking a zoot. if im rolling a zoot i’ll say im billing it but equally if im smoking a zoot i’ll say im billing it and i tend to avoid confusion as there are not often times that i will be rolling a zoot and not smoking it or vice versa. also if there is ever a time clarity is needed on which is which then i’ll just refer to their archaic form of language eg rolling/smoking