Chekhov’s gun
n.— «There’s a literary technique called “Chekhov’s gun” where something introduced early in a story is revealed only later as significant. In Chekhov’s play Uncle Vanya, for example, a pistol is a seemingly irrelevant prop until Uncle Vanya fires it in rage two acts on.» —“Debt to destiny” by Rosie Blau Financial Times (United Kingdom) Sept. 29, 2008. (source: Double-Tongued Dictionary)
Further reading
Centuries ago, monks who took a vow of silence developed their own hand signs, with hundreds of gestures, that are still in use today. Plus, how do speakers of different languages distinguish similar shades and tints of colors such as red, yellow...
Butter of antimony, blue vitriol, flowers of zinc are terms used for centuries by alchemists, now replaced by the scientific names antimony trichloride, cupric sulfate, and powdered zinc oxide. In his delightful memoir Uncle Tungsten: Memories of a...
…which makes “Chekhov’s gun” the opposite of “red herring,” then?