cardboard

noun

1. (countable, uncountable)A wood-based material resembling heavy paper, used in the manufacture of boxes, cartons and signs.
2. (countable, figuratively, uncountable)Something flat or insubstantial.

   “According to these keyboard warriors, the young men and women who survived the shooting are part of a big hoax, are liars, are mere cardboard cutouts – “crisis actors” who roam the country looking for mass shootings from which to promote their anti-gun message – all being pushed forward by the giant liberal machine that is Hillary Clinton’s robot attack army.”

adj

1. Made of or resembling cardboard; (figurative) flat or flavorless.

   “The worst of the thing, however, is that the enormity, such as it is, happens to be of a very cardboard and tinsel character.”

   “The thing really looked quite cardboard.”

   “While Lensky’s character is quite cardboard, Onegin’s manipulations and lack of ability to call off the duel because he fears society’s jibes, Lensky’s youth and naivety, and Tatiana’s reaction to the duel lend the event its gravity.”

   “MUMMER 3 pulls out an inflated cushion with a very cardboard crown on it.”