1. When a thought or idea is lost or forgotten while entering the mind of a human being by a sudden change in the environment. (Most commonly occurring to stoners.)
2. An act to purposely prevent a human being to continue his thought process.
1. I'm totally baked right now typing up this definition of 'Thought Block" and I
2. Friend 1: Man, I just tripped out these two stoners and they forgot where they were going!
Friend 2: Aw, you just though blocked them? You're a dick.