an electromagnetic wave propagating close to the boundaries of a homogeneous dielectric medium with a phase velocity greater than that of the free wave which would exist in an unbounded medium having the same electromagnetic properties Found on http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=705-04-65
an electromagnetic wave propagating close to the boundaries of a homogeneous dielectric medium with a phase velocity greater than that of the free wave which would exist in an unbounded medium having the same electromagnetic properties