"All them nights,
GRINDIN' to get this music out...." or I was in the streets
Grindin', man."
...especially from nikkas with shytty music or people who sell weed. Rappers tend to throw out the "Grindin'" at the drop of a hat.
"Grinding" makes me think of something difficult. Standing in front of a mic and performing your verse is something that most people do while driving their cars and not thinking about it. That is not a grind. That is not back-breaking physical labor.
Now, if you're the guy that's doing the tedious job of recording that wack shyt and eventually mixing/mastering it, I can accept the idea of you grinding...
As for weed dealers....No. Weighing buds & driving around isn't "grinding". Cooking meth without blowing yourself up? Perhaps.