A description of an entity in terms of two spatial dimensions Locations in these two dimensions are often identified by a pair of co-ordinates, x and y
Two-dimensional; as in an X-Y plot; also, referring to the topology of a surface, a plane is 2D A 2D surface can be warped into the third dimension, yet it remains a 2D surface, albeit connecting 3D positions in space This is sometimes referred to as "2 5D" (not a widely acceptable or meaningful term, except among computer graphics types)