I also had to look it up, and found it can be pertaining to various things..alcohol, ecstasy, MDMA, speed...considering he was using the word "grams" I'd say that's a drug conversation.
As far as a drug screen, that's up to you. It will probably have to cover just about anything (hence, more expensive) and random, as A's know how to cheat a test. THEN you have to be ready to impose the consequences you set.
Sorry you're having to deal with this. I would normally ask my 17-year-old niece what it meant, but she's doing her OWN experimentation, went into a rage, and is no longer welcome at our home.
Hugs and prayers,
Amy