Critical Grass

1) N-The immeasurable point at which further inhalation of marijuana smoke will no longer get the user more high, and proceeds to only make the user sleepier.
2) N- The immeasurable point at which your lawn mower bag will hold no more grass.

Ex 1. Jimmy is way past critical grass, I bet he's passed out in an hour.
Ex 2. Load another bowl, I'm along way from critical grass.