1. ozone hole-an area of the ozone layer (near the poles) that is seasonally depleted of ozone. hole-an opening into or through something. ozone layer, ozonosphere-a layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun.ole-an opening into or through something. ozone layer, ozonosphere-a layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun.