Definition of unstable in English:

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Pronunciation: /ˌənˈstābəl/

adjective (unstabler, unstablest)

1Prone to change, fail, or give way; not stable: the unstable cliff tops an unstable government
More example sentences
  • The choice of operation depends on how large the protrusion is, how many nerves are involved and how stable or unstable the spine is.
  • Calm funded the project to avoid safety worries over unstable cliff faces and walking trails.
  • Unfortunately, there are not enough of the biggest bricks which means that the cross section of the tower is only one lego element wide at the top and very unstable.
1.1Prone to psychiatric problems or sudden changes of mood: he was mentally unstable
More example sentences
  • So I didn't want to open the door to the mental hospital, but I was forced to because of her unstable state.
  • The diagnosis is that of an emotionally unstable borderline personality disorder.
  • The ruling affected the treatment of mentally unstable prisoners during trials.
unbalanced, of unsound mind, mentally ill, deranged, demented, disturbed, unhinged, volatile
informal kooky



Example sentences
  • The highly accomplished actress gets some details right, but the overarching mental unstableness she exudes is so excessive as to make one wonder whether she is playing or being unhinged.
  • Her mental unstableness is too hard for her to cope with.
  • Her mother and father snub her off completely overlooking her serious unstableness.


Pronunciation: /-blē/
Example sentences
  • Deciding that a cold shower would be a much saner solution, he disentangled himself from his blanket and walked unstably towards the bathroom, all the while trying to remember what exactly happened that led him to this position.
  • Forty-five percent were homeless or unstably domiciled, over three-fourths were living as single, and 89% were unemployed.
  • Her knees shook unstably, and she headed towards the chair.

For editors and proofreaders

Syllabification: un·sta·ble

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