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.

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Etymology

Origin of parallel universe

First recorded in 1920–25

Example Sentences

Smacking his head on a lamppost while chasing one woman and ogling another, Damien is transported to a parallel universe in which women don’t just run the world, the nature of the sexes has flipped.

From The Wall Street Journal • May 22, 2026

He said having to be brought home afterwards in a police car was like being in a "parallel universe".

From BBC • May 17, 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

Surely Gunn wrote this relatable parallel universe A-plot into “Peacemaker” with an understanding of how potent a proposition it is to viewers these days.

From Salon • Aug. 21, 2025

But this isn’t my usual mall, which means it’s like stepping into a parallel universe.

From "Leah on the Offbeat" by Becky Albertalli