A wedge or similar device inserted in a space adjacent to an object, to hold the object steady. 

When an underground storage tank is delivered to a construction site, it often remain on the ground for several days prior to installation. As a result of wind or uneven surfaces, the tanks may tend to roll. Such movement can cause abrasions in the tanks’ coatings or damage to the tanks’ structures. 

To prevent movement of tanks in temporary storage at a jobsite, the tanks should be chocked. That is, something should be wedged under the lower quadrant of each tank to keep it from rolling.