Source : Free On-Line Dictionary of Computing

Delaunay triangulation
     
         (After B. Delaunay) For a {set} S of
        points in the {Euclidean plane}, the unique {triangulation}
        DT(S) of S such that no point in S is inside the circumcircle
        of any triangle in DT(S).  DT(S) is the dual of the {voronoi
        diagram} of S.