Source : Free On-Line Dictionary of Computing

voxel
     
         (By analogy with "{pixel}") Volume element.
     
        The smallest distinguishable box-shaped part of a
        three-dimensional space.  A particular voxel will be
        identified by the x, y and z coordinates of one of its eight
        corners, or perhaps its centre.  The term is used in three
        dimensional modelling.
     
        (1995-03-10)