parallel universe

American  

[par-uh-lel yoo-nuh-vurs] / ˈpær əˌlɛl ˈyu nəˌvɜrs /

noun

1. Physics. any of a hypothetical collection of undetectable universes that are like our known universe but have branched off from our universe due to a quantum-level event.

2. (in cosmology) a hypothetical universe that coexists with our known universe but may operate under fundamentally different laws of physics.

3. Also called alternate universe,.  Also called alternative universe.  (in science fiction, fantasy, etc.) a separate universe or world that coexists with our known universe but is very different from it.

4. a realm of existence and experience that is fundamentally different from the one that most humans share; a separate reality.

   I don’t understand him—I think he lives in a parallel universe.

---

Etymology

Origin of parallel universe

First recorded in 1920–25

Example Sentences

Of course, no influencer plot would be complete without the threat of online cancellation — and just when things can’t get any worse, Natalie enters the parallel universe of the past.

From Los Angeles Times • Apr. 7, 2026

Rodeo FX worked on seasons four and five of the Netflix show that follows a group of teenagers in small town America as they take on supernatural creatures and a parallel universe.

From Barron's • Jan. 31, 2026

After all, the entry point to this parallel universe is a tony study inside a well-appointed McMansion.

From Salon • Oct. 2, 2025

He eventually found empathy for Chris by bringing himself into the story, imagining the events of the film were happening to him in a parallel universe.

From Los Angeles Times • Nov. 22, 2024

There’s this strangeness, like when you accidentally turn one street too early, and, because all of the cookie-cutter houses look the same, you feel as if you’re in a parallel universe.

From "Dry" by Neal Shusterman and Jarrod Shusterman