fun size vs immature

fun size

noun
  • A small size. 

adj
  • Small in size. 

immature

noun
  • An immature member of a species. 

adj
  • Not fully formed or developed; not grown. 

  • Childish in behavior; juvenile. 

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