laterality

from WordNet (r) 3.0 (2006)

laterality
    n 1: localization of function on either the right or left sides
         of the brain [syn: {lateralization}, {lateralisation},
         {laterality}]
    2: the property of using one hand more than the other [syn:
       {handedness}, {laterality}]
    3: superior development of one side of the body [syn:
       {laterality}, {dominance}]

from The Collaborative International Dictionary of English v.0.48

Laterality \Lat`er*al"i*ty\, n.
   The state or condition of being lateral.
   [1913 Webster]