also two dimensional
1.
A two-dimensional object or figure is flat rather than solid so that only its length and width can be measured.
...new software, which generates both two-dimensional drawings and three-dimensional images.
ADJ : usu ADJ n
2.
If you describe fictional characters as two-dimensional , you are critical of them because they are very simple and not realistic enough to be taken seriously.
I found the characters very two-dimensional, not to say dull.
ADJ [ disapproval ]