Term for when somebody has reached the physical or mental peak of being high, namely on marijuana. Reaching Maximum-Altitude means that a person cannot/will not smoke anymore because they believe they can't possibly get any higher.
"Dude we've smoked 7 bowls, wanna go for an eighth?"
"No way. I'm at Maximum Altitude, I can barely move."
"No way. I'm at Maximum Altitude, I can barely move."
by The Guru of Ganja November 2, 2013