Used as a replacement for a wide variety of words, as a substitute .
"You have some gritweed stuck in your teeth!" .Replaces lettuce or whatever the fuck in stuck there.
"Your ass smells like gritweed is rotting in it!!" Replaces "something crawled in and died".
Therefore use it wherever appropriate. Who gives a shit if they don't understand...you'll be laughing.
Cannabis (marijuana) laced with silica glass. It causes the buds to be heavier and creates a lethal product. Found in the UK, examine your buds and rub them on glass and if it scrapes than it is tainted. Throw it away, it can be lethal.
John smoked some grit weed, he lost his voice and kept coughing up blood, had to take him to the hospital.