Source : Webster's Revised Unabridged Dictionary (1913)

Asymmetry \A*sym"me*try\, n. [Gr. ?; 'a priv. + ? symmetry.]
   1. Want of symmetry, or proportion between the parts of a
      thing, esp. want of bilateral symmetry.

   2. (Math.) Incommensurability. [Obs.] --Barrow.

Source : WordNet®

asymmetry
     n : (mathematics) a lack of symmetry [syn: {imbalance}] [ant: {symmetry}]