1. Theological/Judgment Day
    • In many religious traditions (notably within Christianity, Islam, and Judaism), “Doomsday” refers to the Final Judgment—the day when the divine judges all souls and brings an end to the present world order.
    • It’s often synonymous with “Judgment Day” or “Day of Reckoning.”
  2. Apocalyptic “End of the World”
    • More broadly, “doomsday” describes any scenario in which civilization (or even life on Earth) is catastrophically ended.
    • Typical themes include:
      • Natural disasters: massive asteroid impacts, super‐volcano eruptions, deadly pandemics
      • Human‐made catastrophes: nuclear war, runaway climate change, engineered bioweapons
      • Cosmic events: gamma‐ray bursts, the sun going supernova billions of years hence
  3. Popular‐Culture & Fiction
    • Doomsday scenarios are staples of films, novels, comics, and games. From George Miller’s Mad Max wastelands to the “Day After Tomorrow” climate‐crash thriller, they explore what society—and individuals—would look like when all systems collapse.
    • The name “Doomsday” itself even appears as a super‐villain in DC Comics, famous for “killing” Superman.
  4. Metaphorical Usage
    • People often use “doomsday” hyperbolically to warn about potential disasters: “if we don’t address climate change now, it’ll be doomsday for coastal cities.”
    • In this sense it’s shorthand for “utter disaster” or “point of no return.”
  5. “Doomsday Clock”
    • The Bulletin of the Atomic Scientists maintains a symbolic “Doomsday Clock,” whose hands indicate how close humanity is—via nuclear risk, climate change, and emerging technologies—to “midnight,” i.e., global catastrophe.

Key Takeaways

  • Etymology: From Middle English domesdei (“day of judgment”), itself from Old English dōmdæg.
  • Core meaning: A final, irrevocable end—whether divine judgment or planetary annihilation.
  • Usage: Can be literal (religious), fictional (genre), or metaphorical (everyday warnings).

By understanding these layers—religious, scientific, cultural, and metaphorical—you get a full sense of what “doomsday” encompasses.