allusion

noun

1. (countable, uncountable)An indirect reference; a hint; a reference to something supposed to be known, but not explicitly mentioned.

   “I remember, before the Dwarf left the Queen, he followed us one day into thoſe gardens, and my Nurſe having ſet me down, he and I being cloſe together, near ſome Dwarf Apple trees, I muſt need ſhew my Wit, by a ſilly Alluſion between him and the Trees, which happens to hold in their Language as it doth in ours.”

   “In order to understand some of the allusions readers must remember that the Autobiography was originally written in the form of "epistles addressed to Mr. Robert Riddell at London, by his friend and relative," to which, in their collected form, the author had given the title "Obscurities in Private Life Developed; or, Robinson Crusoe Untravelled."”

   “The influence of Lucretius on Virgil was pervasive, especially in Virgil's Georgics; and it is in clear allusion to Lucretius that Virgil wrote, “Happy is the man who can read the causes of things.””