Definitions for "Drywell"
A hole dug to a depth above the water table so that its bottom and sides are typically dry except when receiving fluid discharged from an industrial process. Is often filled with gravel or is reinforced with concrete blocks to form a chamber.
a bored, drilled, or driven shaft or hole whose depth is greater than its width and is designed and constructed specifically for the disposal of stormwater
a drum or tank in the ground, full of holes (and now bottom) that can accept your drains and then let them seep into the ground away from your foundation