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

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

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

In these environments, dark energy plays almost no role.

From Science Daily • Mar. 10, 2026

That effect is known as "dark energy," the name scientists use to describe the accelerated expansion of the universe.

From Science Daily • Mar. 10, 2026

As though plunder of dark energy was not at the heart of our galaxy.

From "Between the World and Me" by Ta-Nehisi Coates