Answer:
It is the area on opposite side of the earth from an earthquake where no s waves are picked up by seismographs.
Explanation:
Shadow zone of an earthquake is one which is farthest from the epicenter. Hence it is not the area closest to earthquake.
In shadow zone only the S waves are stopped by whereas P waves through refracted, travel through and are measured in seismograph. Hence it is an area where there are few seismographs.
The zone is not constant and each epicenter has its own shadow zone. The shadow zone was caused by the inability of s waves to pass through the liquids. This proved the presence of liquid layer in earth's core. Hence the shadow zone is not the outer molten core of earth but the zone was caused by the molten core.
Hence the shadow zone of an earth quake is the area on opposite side of the earth from an earthquake where no s waves are picked up by seismographs.