ozone hole

English Thesaurus

1. an area of the ozone layer (near the poles) that is seasonally depleted of ozone (noun.object)

hypernym	:	hole,
definition	:	an opening into or through something (noun.object)

part meronym	:	ozone layer, ozonosphere,
definition	:	a layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun (noun.object)