Tibino is greek slang for "I smoke weed" or "I'm
smoking weed". It literally means "I drink her/I'm drinking her" and is the
combination of the two words that make up the phrase in greek i.e. "την πίνω". We say it like this because
consumption of drugs is often referred to as drinking, you can "drink" xannies (ζάνια), free-base (φρίμπες) etc. Tibino is more specific though, as the "her" contained in the phrase signifies you're talking about Mary Jane.
Bonus: You can throw in some absurd word after Tibino to convey the severity of your session or habit.