The over-enthusiastic use of one's hands when behind the camera to emphasize what they are talking about, and avoid still-handed awkwardness. Most frequently used by sports announcers and meteorologists.
When one shreds the knar so hard that the location of such a knarly endevour deserves just classification. Shreditoriums are often located in high elevation mountainous regions which is consequently the natural habitat for shredders.
I just took a visit to the shreditorium brochacho! There were sick shoots and cliff-drops everywhere!