The Collaborative International Dictionary of English v.0.48:

Misproportion \Mis`pro*por"tion\, v. t.
   To give wrong or unesthetic proportions to; to join without
   due proportion; as, the legs were misrpoportioned to the
   body.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

misproportion \mis`pro*por"tion\, n.
   An improper or unesthetic proportion.
   [PJC]