cardboard vs fun

cardboard

noun
  • A wood-based material resembling heavy paper, used in the manufacture of boxes, cartons and signs. 

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

fun

noun
  • playful, often noisy, activity. 

  • amusement, enjoyment or pleasure 

adj
  • Enjoyable or amusing. 

  • Whimsical or flamboyant. 

verb
  • To tease, kid, poke fun at, make fun of. 

How often have the words cardboard and fun occurred in a corpus of books? (source: Google Ngram Viewer )