lacking the expected range or depth; not designed to give an illusion or depth; 2-dimensional, flat
a film with two-dimensional characters
a flat two-dimensional painting
Microsoft Computer Dictionary
adj. Existing in reference to two measures, such as height and width—for example, a two-dimensional model drawn with reference to an x-axis and a y-axis, or a two-dimensional array of numbers placed in rows and columns. See also Cartesian coordinates.