a zone in the upper mantle of the earth, consisting of hot, plastic rock, that underlies the solid lithosphere
Origin of asthenospherefrom Classical Greek asthen?s, weak (see asthenia) + -o- + -sphere
A zone of the earth's mantle that lies beneath the lithosphere and consists of several hundred kilometers of deformable rock.
Origin of asthenosphereGreek asthenēs weak ; see asthenia . sphere
From Ancient Greek ἀσθενής (asthenēs, “weak”) + sphere.