Best definition
a green plant substance often boiled down with cooking butter to create a greener shade of butter, that then can

be used to prepare cookies of some description.
there are many other uses of “zubast” eg mixing it with tobacco and rolling it up in a thin paper with an adhesive strip (after sufficient lubrication – often with saliva)to create a white cylindrical item that then can be ignited,while air is pulled through it by means similar to that of breathing.

“yo sup my nigga? how much did those 3 Gs of zubast cost you?”

“40 bucks”

“fuck man u got ripped off”