a material made of paper pulp but thicker and stiffer than paper; pasteboard: used for making cards, boxes, etc.
adjective
of or like cardboard
insubstantial or flimsy: a cardboard empire
superficial or shallow: cardboard characters in a play
See cardboard in American Heritage Dictionary 4
noun
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.
adjective
Made of or consisting of cardboard.
a. Flimsy; insubstantial.
b. Lacking depth; superficial: a movie with only cardboard caricatures of its historical subjects.