metastable

American  

[met-uh-stey-buhl, met-uh-stey-] / ˈmɛt əˌsteɪ bəl, ˌmɛt əˈsteɪ- /

adjective

1. Metallurgy. chemically unstable in the absence of certain conditions that would induce stability, but not liable to spontaneous transformation.

2. Physics, Chemistry. Also pertaining to a body or system existing at an energy level metastable state above that of a more stable state and requiring the addition of a small amount of energy to induce a transition to the more stable state.

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metastable British  

/ ˌmɛtəˈsteɪbəl /

adjective

1. (of a body or system) having a state of apparent equilibrium although capable of changing to a more stable state

2. (of an atom, molecule, ion, or atomic nucleus) existing in an excited state with a relatively long lifetime

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noun

1. a metastable atom, ion, molecule, or nucleus

Other Word Forms

• metastability
  noun

Etymology

Origin of metastable

First recorded in 1895–1900; meta- + stable ²

Example Sentences

See Examples For:

metastable

Pairing that metastable phase with a O3-type cathode that has been coated with a chloride-based solid electrolyte can create thick, high-areal-loading cathodes that puts this new design beyond previous sodium batteries.

From Science Daily ● Oct. 17, 2025

Li ions move to the nearest Li position always passing through metastable positions.

From Science Daily ● Apr. 2, 2024

Immobile La3+ bonded to F ion inhibits the Li-ion conduction by blocking the conduction path and vanishing the surrounding metastable positions.

From Science Daily ● Apr. 2, 2024

Visible light excites the atoms or molecules to metastable states that decay slowly, releasing the stored excitation energy partially as visible light.

From Textbooks ● Aug. 12, 2015

It's a metastable state at best, all too likely to collapse into tyranny.

From The Sensitive Man by Poul William Anderson