  We redefine the surface tension coefficient for a nuclear Fermi-liquid drop
with a finite diffuse layer. Following Gibbs-Tolman concept, we introduce the
equimolar radius R_e of sharp surface droplet at which the surface tension is
applied and the radius of tension surface R_s which provides the minimum of the
surface tension coefficient \sigma. This procedure allows us to derive both the
surface tension and the corresponding curvature correction (Tolman length)
correctly for the curved and diffuse interface. We point out that the curvature
correction depends significantly on the finite diffuse interface. This fact is
missed in traditional nuclear considerations of curvature correction to the
surface tension. We show that Tolman's length \xi is negative for nuclear
Fermi-liquid drop. The value of the Tolman length is only slightly sensitive to
the Skyrme force parametrization and equals \xi=-0.36 fm.
