A stiff compact pasteboard of various qualities, for making cards, etc., often having a polished surface.
- A material similar to thick, stiff paper, that is made of pressed paper pulp or pasted sheets of paper. It is used for making cartons and signs, for example.
- Made of or consisting of cardboard.
- Flimsy; insubstantial.
- Lacking depth; superficial: a movie with only cardboard caricatures of its historical subjects.