  The surface of W(110) exhibits a Dirac-cone-like surface state with $d$
character within a spin-orbit-induced symmetry gap. As a function of wave
vector parallel to the surface, it shows nearly massless energy dispersion and
a pronounced spin polarization, which is antisymmetric with respect to the
Brillouin zone center. In addition, the observed constant energy contours are
strongly anisotropic for all energies. This discovery opens new pathways to the
study of surface spin-density waves arising from a strong Fermi surface nesting
as well as $d$-electron-based topological properties.
