to spoil the form or appearance of (something)
to make (something) ugly or monstrous
to alter the shape of (something) by stress
to become misshapen or changed in shape, esp by stress
deformable adj
deformation /defəʹmaysh(ə)n/ noun
deformational /defəʹmaysh(ə)nl/ adj
[Middle English deformen via Frenchfrom Latin deformare, from de- + formare to form, from forma form1]