allusion

noun
  1. An indirect or passing reference to an event, person, place, or artistic work, which is not explicitly mentioned but is assumed to be known by the reader or listener. noun
    The novel's title is an allusion to Shakespeare's play.
    Her speech contained an allusion to the famous historical event.
  2. The act of making an indirect reference to something. noun
    His allusion to the economic crisis was subtle but effective.
    The poem is rich in allusions to classical mythology.