\Un`sym*met"ric*al\, a.
1. Wanting in symmetry, or due proportion pf parts.
2. (Biol.) Not symmetrical; being without symmetry, as the
   parts of a flower when similar parts are of different size
   and shape, or when the parts of successive circles differ
   in number. See {Symmetry}.
3. (Chem.) Being without symmetry of chemical structure or
   relation; as, an unsymmetrical carbon atom.
{Unsymmetrical carbon atom} (Chem.), one which is united at
   once to four different atoms or radicals. This condition
   usually occasions physical isomerism, with the attendant
   action on polarized light.