Definition of unstable in English:

unstable

adjective

  • 1Likely to give way; not stable.

    ‘the unstable cliff tops’
    • ‘Even when it was discovered that the land was unstable and prone to landslide, the squatters remained.’
    • ‘The slopes and cliffs reflect a highly unstable and dynamic landscape.’
    • ‘As you might be aware, Tokyo is built on some slightly unstable land, prone to all manner of natural disasters, especially earthquakes.’
    • ‘Following this extended period of stability the slope, whilst still grazed grassland, suddenly became unstable.’
    • ‘The choice of operation depends on how large the protrusion is, how many nerves are involved and how stable or unstable the spine is.’
    • ‘The last remaining member of the Hail family rose from her seat, balancing precariously on unstable legs.’
    • ‘Death of the whole tree will not be immediate, but reduced root development will make the larger trees unstable and therefore prone to wind-blow.’
    • ‘Officers said overloaded caravans were unstable and difficult to control.’
    • ‘Construction of drilled piles in unstable soil is difficult because soil can contaminate the pile.’
    • ‘Yet this one is so poorly made that the mast at sea would have twisted, making the ship unstable and difficult to control.’
    • ‘However it was found to be geologically unstable and would likely blow itself to ashes in about six cycles.’
    • ‘Just inside the entrance many large rocks had fallen and lots of loose rubble, indicating that the entrance was unstable and prone to rock falls.’
    • ‘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.’
    • ‘Calm funded the project to avoid safety worries over unstable cliff faces and walking trails.’
    • ‘Luckily, it caught a jar full of pencils, already unstable and perched precariously on the edge of the desk.’
    • ‘Conditions in the mine were so unstable that rescue workers could not enter the shaft to retrieve the bodies for almost 24 hours.’
    • ‘Due to natural erosion the cliff was inherently unstable, and there had been at least two landslips on the authority's land.’
    • ‘The thief and his pursuers were uncertain on their feet while they tried to traverse the unstable landscape.’
    • ‘The unstable ground underneath his feet suddenly gave way, and he fell into a deep sinkhole.’
    • ‘Such steep slopes are unstable and prone to slumping, so deltas often collapse.’
    unsteady, rocky, wobbly, wobbling, rickety, shaky, tottery, tottering, teetering, doddery, unsafe, unbalanced, unreliable, insecure, not secure, unfastened, unsecured, movable, precarious
    View synonyms
    1. 1.1Likely to change or fail; not firmly established.
      ‘an unstable government’
      • ‘Unstable voltage lines mean an unstable system and this is the last thing people want.’
      • ‘Nuclear power is like that - unpredictable, unstable and ultimately as dangerous as it gets.’
      • ‘At the same time, the incomes - and jobs - they do have are far more unstable than they were a few decades ago.’
      • ‘Without citizens who possess these qualities, democracies become difficult to govern, even unstable.’
      • ‘The problem is from the ground up it's a very unstable technology in terms of specifications.’
      • ‘However, you could be forgiven for thinking that the future for competitive operators looks highly uncertain and unstable.’
      • ‘The conditions of patients admitted to the trauma room are usually unstable and critical.’
      • ‘Wahid, at the head of an unstable multi-party coalition, is attempting a precarious political balancing act.’
      • ‘The subjectivity of decisions made by these people makes global financial markets extremely unstable.’
      • ‘He said that the difficulties also led to the highly unstable domestic prices and deterioration in living conditions.’
      • ‘Today they read as uncanny reflections of our own unstable, uncertain age.’
      • ‘Experts have said that the unstable exchange rate created difficulties in reaching debt restructuring agreements.’
      • ‘Throughout the 1990s, politics were extremely unstable, with frequent changes of government.’
      • ‘However, base rates are inherently ambiguous, unreliable and unstable.’
      • ‘Other staff contend with phone lines that don't work, uncertain supply lines, and a power system that is unstable at the best of times.’
      • ‘They are the future of our country and if we allow a bad situation get worse, then we are setting the country on a road to an unstable and uncertain future.’
      • ‘It is a very unstable region, where changes can occur brutally.’
      • ‘The economy is unstable and unpredictable, and people have to adapt to many changes to survive.’
      • ‘It is not necessary to point out that when the economy is on track, the unstable labor market problem resolves itself.’
      • ‘Political fragmentation has been a problem, and coalitions between parties have been unstable.’
    2. 1.2Prone to psychiatric problems or sudden changes of mood.
      ‘he was mentally unstable’
      • ‘Both emotionally stable and unstable students can benefit from a better understanding of psychology.’
      • ‘We are expecting that the western media will portray him a crazy or an unstable person - he was the opposite.’
      • ‘He is accusing this woman of mentally unstable demeanour when, in fact, he seems to be the most qualified for such a label.’
      • ‘Police say Bazell, who had a ticket for a domestic Delta flight, appeared mentally unstable.’
      • ‘Defence counsel argued that Cowle was mentally unstable, but the prosecution said he was not insane in the legal sense.’
      • ‘The men became uncontrollable, emotionally unstable and dangerously paranoid.’
      • ‘Leading up to her death, the weeks before her death, many people seemed to think she was mentally unstable.’
      • ‘The diagnosis is that of an emotionally unstable borderline personality disorder.’
      • ‘The ruling affected the treatment of mentally unstable prisoners during trials.’
      • ‘So I didn't want to open the door to the mental hospital, but I was forced to because of her unstable state.’
      • ‘When a suspect is mentally unstable, officers are trained to back off and call in a crisis intervention team.’
      • ‘Women, in comparison to men, also viewed the defendant as more psychologically unstable.’
      • ‘A hitman is assigned to kidnap the mentally unstable younger brother of a powerful district attorney.’
      • ‘When one is emotionally unstable, alcohol inhibits the ability to confront and solve problems.’
      • ‘From seventeen year old kid with an unstable mother to his rise as a porn god to his fall from grace, Wahlberg is there every step of the way.’
      • ‘If Khouri is as mentally unstable as the article implies then that's a bit harsh, don't you reckon?’
      • ‘It appears that he had a lively genius, but was unstable, erratic, and weak.’
      • ‘Ray Liotta plays a reckless and unstable crime boss.’
      • ‘Betty is a successful writer who is forced to relive her traumatic childhood when her mentally unstable mother comes to visit.’
      • ‘There are, unfortunately, people in the world who are unstable, and who may descend into madness.’

Pronunciation:

unstable

/ʌnˈsteɪb(ə)l/