1 definition by Dimitri Eleanor Roosevelt, III

The act of smoking marijuana. So much marijuana is smoked that the area resembles an outdoor bog. A foggy bog.
Example 1: OH, man, I'm so burnt out. We fogged up last night; I ate a Hot Pocket straight out of the freezer.

Example 2: Wanna fog up after class? We can watch my cats play in my backyard.
Get the Fog up mug.