1. a layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun; [syn: ozone layer, ozonosphere]
WordNet (r) 3.0 (2006):
ozone layer
n 1: a layer in the stratosphere (at approximately 20 miles)
that contains a concentration of ozone sufficient to block
most ultraviolet radiation from the sun [syn: ozone
layer, ozonosphere]