Cardboard
Part of speech: noun
Definition: A wood-based material resembling heavy paper, used in the manufacture of boxes and signs.
Example sentence: My father bought me a little cardboard accordion, and when I was three I got this little machine.
Artificial
Part of speech: adjective
Definition: Man-made; of artifice.False, misleading.Unnatural.
Example sentence: To the soul, there is no past and no future; all is, and will be ever, in now. For artificial purposes time is mutually agreed on, but there is really no such thing.