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


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

Origin of metastable

First recorded in 1895–1900; meta- + stable2


met·a·sta·bil·i·ty [met-uh-stuh-bil-i-tee] /ˌmɛt ə stəˈbɪl ɪ ti/, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for metastable

British Dictionary definitions for metastable

/ (ˌmɛtəˈsteɪbəl) physics /


(of a body or system) having a state of apparent equilibrium although capable of changing to a more stable state
(of an atom, molecule, ion, or atomic nucleus) existing in an excited state with a relatively long lifetime


a metastable atom, ion, molecule, or nucleus

Derived forms of metastable

metastability, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012