A blah is another name for rolled up Cannabis. It is made from the plant Cannabis Sativa. It's intended purpose is for use as a psychoactive (mind-altering) drug.
The main psychoactive ingredient in a blah is THC (delta-9-tetrahydrocannabinol), but more than 400 other chemicals also are in the plant.
Immediate physical effects of a blah include a faster heartbeat and pulse rate, bloodshot eyes, and a dry mouth and throat.
A blah is normally made by taking a cigarette and replacing out the tobacco with cannabis. A blah can also be made by using rolling paper and a filter.
It is common practice to smoke a blah in a group and follows the concept of puff-and-pass.
1. That blah got me so high!
2. Yesterday, i smoked a blah with my friends.
3. We took the weed out the blah and put it in the pipe instead.