in-joke vs mock

in-joke

noun
  • Synonym of inside joke (“a joke that is understood or meant to be understood only by certain people who are aware of the details”) 

mock

noun
  • Mockery; the act of mocking. 

  • A practice exam set by an educating institution to prepare students for an important exam. 

  • A mockup or prototype; particularly, ellipsis of mock object., as used in unit testing. 

  • An imitation, usually of lesser quality. 

adj
  • Imitation, not genuine; fake. 

verb
  • To create a mockup or prototype of. 

  • To mimic, to simulate. 

  • To create an artistic representation of. 

  • To tantalise, and disappoint the hopes of. 

  • To make fun of, especially by mimicking; to taunt. 

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