An Affine Transformation in which the scale is reduced. A dilation is also known as a Contraction or Homothecy. Any dilation which is not a simple translation has a unique Fixed Point. The opposite of a dilation is an Expansion.
See also Affine Transformation, Expansion, Homothecy
Coxeter, H. S. M. and Greitzer, S. L. Geometry Revisited. Washington, DC: Math. Assoc. Amer., pp. 94-95, 1967.