ground state

American  

noun

Physics.

1. the state of least energy of a particle, as an atom, or of a system of particles.

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ground state British  

noun

1. the lowest energy state of an atom, molecule, particle, etc Compare excited

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ground state Scientific  

1. The state of a physical system having the lowest possible potential energy. For example, an electron in the lowest energy orbital in a hydrogen atom is in a ground state. The ground state of a physical system tends to be stable unless energy is applied to it from the outside; states that are not the ground state have a tendency to revert to the ground state, giving off energy in the process.

2. Compare excited state

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Etymology

Origin of ground state

First recorded in 1925–30

Compare meaning

How does ground-state compare to similar and commonly confused words? Explore the most common comparisons:

• ground state vs. excited state
• excited vs. ground state

Example Sentences

In recent months, the carrier group has been hit by a wave of strikes by pilots, but agreed last month to increase wages of ground staff in Germany, addressing another potential cause for disruption.

From The Wall Street Journal • Apr. 16, 2026

Despite the controversy, MCG chief executive Stuart Fox backed Page and his ground staff to continue.

From Barron's • Dec. 28, 2025

Before the first of those meetings, Mourinho is alleged to have instructed the ground staff at the Bernabeu to let the grass grow longer to combat Barca's quick-paced, short passing style.

From BBC • Nov. 10, 2025

It said the two ground staff died after falling into the water.

From The Wall Street Journal • Oct. 20, 2025

One of the ground staff wrote the letter for her, perching on the wing of Lilya’s plane.

From "A Thousand Sisters" by Elizabeth Wein