dark energy

American  

[dahrk en-er-jee] / ˈdɑrk ˈɛn ər dʒi /

noun

1. a hypothetical form of energy whose negative pressure counteracts gravity and is assumed to be responsible for the universe expanding at an accelerating rate.

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dark energy Scientific  

1. A form of energy hypothesized to reside in the structure of space itself, responsible for the accelerating expansion of the universe. Dark energy theoretically counterbalances the kinetic energy of the universe's expansion, entailing that that the universe has no inherent curvature, as astronomical observations currently suggest. Dark energy appears to account for 73 percent of all the energy and matter in the universe.

2. See also big bang

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dark energy Cultural  

1. An as yet unknown and unidentified form of energy that pervades the universe and produces a force that counteracts the gravitational attraction between galaxies.

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Discover More

Dark energy is thought to be responsible for the accelerating universe.

Etymology

Origin of dark energy

First recorded in 1995–2000

Example Sentences

But Roman will also study the invisible -- dark matter and dark energy, whose origins remain unknown but which are thought to constitute 95 percent of our universe.

From Barron's • Apr. 22, 2026

Dark matter is believed to be the glue that holds galaxies together, while dark energy pulls them apart by making the universe expand faster and faster over time.

From Barron's • Apr. 22, 2026

Astronomers may be getting closer to understanding one of the biggest mysteries in cosmology: dark energy, the unknown force believed to be driving the accelerating expansion of the universe.

From Science Daily • Mar. 16, 2026

As dark energy pushes space outward, the voids expand and press against the surrounding cosmic web.

From Science Daily • Mar. 10, 2026

A bolt of dark energy shot toward me, but I deflected it off my blade and slammed into him.

From "The Last Olympian" by Rick Riordan