I. ˈkärd-ˌbȯrd noun
Date: 1831
: a material made from cellulose fiber (as wood pulp) like paper but usually thicker
• card·boardy -ˌbȯr-dē adjective
II. adjective
Date: 1852
1. : made of or as if of cardboard
2. : unreal , stereotyped
a play with cardboard characters