unstable

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un·sta·ble

(ŭn-stā′bəl)

adj. un·sta·bler, un·sta·blest

a. Tending strongly to change: unstable weather.

b. Not constant; fluctuating: unstable vital signs.

a. Wavering or fickle: At first, he was unstable in his decisions.

b. Showing or marked by erratic or volatile emotions or behavior.

3. Not firmly placed; unsteady: an unstable ladder.

4. Chemistry

a. Decomposing readily.

b. Highly or violently reactive.

5. Physics

a. Decaying with relatively short lifetime. Used of subatomic particles.

b. Radioactive.

un·sta′ble·ness n.

un·sta′bly adv.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

unstable

(ʌnˈsteɪbəl)

adj

1. lacking stability, fixity, or firmness

2. disposed to temperamental, emotional, or psychological variability

3. (Chemistry) (of a chemical compound) readily decomposing

4. (Atomic Physics) physics

a. (of an elementary particle) having a very short lifetime

b. spontaneously decomposing by nuclear decay; radioactive: an unstable nuclide.

5. (Electronics) electronics (of an electrical circuit, mechanical body, etc) having a tendency to self-oscillation

unˈstableness n

unˈstably adv

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

un•sta•ble

(ʌnˈsteɪ bəl)

adj.

1. not stable; not firm or firmly fixed; unsteady.

2. liable to change or fluctuate quickly: an unstable weather pattern.

3. marked by emotional instability.

4. unsteadfast; inconstant; wavering.

5. irregular in movement.

6. noting chemical compounds that readily decompose or change into other compounds.

[1175–1225]

un•sta′ble•ness, n.

un•sta′bly, adv.

un·sta·ble

(ŭn-stā′bəl)

1. Liable to change spontaneously into a nucleus or atomic particle with less mass. For example, the nucleus of uranium 238 is unstable and changes by radioactive decay into the nucleus of thorium 234, a lighter element.

2. Relating to a chemical compound that decomposes or changes into other compounds or into elements easily. Candle wax, for example, which is made of a mixture of hydrocarbons, decomposes into carbon dioxide and water when it reacts with oxygen during combustion.

3. Relating to an atom or chemical element that is likely to share electrons; reactive.

The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

ThesaurusAntonymsRelated WordsSynonymsLegend:

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Adj.	1.	unstable - lacking stability or fixity or firmness; "unstable political conditions"; "the tower proved to be unstable in the high wind"; "an unstable world economy" inconstant - likely to change frequently often without apparent or cogent reason; variable; "inconstant affections"; "an inconstant lover"; "swear not by...the inconstant moon"- Shakespeare impermanent, temporary - not permanent; not lasting; "politics is an impermanent factor of life"- James Thurber; "impermanent palm cottages"; "a temperary arrangement"; "temporary housing" unsteady - subject to change or variation; "her unsteady walk"; "his hand was unsteady as he poured the wine"; "an unsteady voice" stable - resistant to change of position or condition; "a stable ladder"; "a stable peace"; "a stable relationship"; "stable prices"
	2.	unstable - highly or violently reactive; "sensitive and highly unstable compounds" reactive - participating readily in reactions; "sodium is a reactive metal"; "free radicals are very reactive"
	3.	unstable - affording no ease or reassurance; "a precarious truce" precarious uneasy - lacking a sense of security or affording no ease or reassurance; "farmers were uneasy until rain finally came"; "uneasy about his health"; "gave an uneasy laugh"; "uneasy lies the head that wears the crown"; "an uneasy coalition government"; "an uneasy calm"; "an uneasy silence fell on the group"
	4.	unstable - suffering from severe mental illness; "of unsound mind" mentally ill, unsound insane - afflicted with or characteristic of mental derangement; "was declared insane"; "insane laughter"
	5.	unstable - disposed to psychological variability; "his rather unstable religious convictions" irresolute - uncertain how to act or proceed; "the committee was timid and mediocre and irresolute"
	6.	unstable - subject to change; variable; "a fluid situation fraught with uncertainty"; "everything was unstable following the coup" fluid changeful, changeable - such that alteration is possible; having a marked tendency to change; "changeable behavior"; "changeable moods"; "changeable prices"

unstable

adjective

1. changeable, volatile, unpredictable, variable, fluctuating, unsteady, fitful, inconstant The situation is unstable and potentially dangerous.
changeable stable, steady, predictable, constant

2. insecure, shaky, precarious, unsettled, wobbly, tottering, rickety, unsteady, not fixed a house built on unstable foundations

3. unpredictable, irrational, erratic, inconsistent, unreliable, temperamental, capricious, changeable, untrustworthy, vacillating He was emotionally unstable.
unpredictable rational, level-headed, stable, consistent, reliable, trustworthy

Collins Thesaurus of the English Language – Complete and Unabridged 2nd Edition. 2002 © HarperCollins Publishers 1995, 2002

unstable

adjective

1. Capable of or liable to change:

alterable, changeable, fluid, inconstant, mutable, uncertain, unsettled, unsteady, variable, variant.

Archaic: various.

2. Following no predictable pattern:

capricious, changeable, erratic, fantastic, fantastical, fickle, freakish, inconsistent, inconstant, mercurial, temperamental, ticklish, uncertain, unpredictable, unsteady, variable, volatile, whimsical.

3. Lacking stability:

infirm, insecure, precarious, shaky, tottering, tottery, unsteady, unsure, weak, wobbly.

4. Not physically steady or firm:

precarious, rickety, shaky, tottering, tottery, unsteady, wobbly.

Translations

غَيْرُ مُسْتَقِرّ

nestabilní

ustabil

horjuva

nestabilan

instabile labile volubile alterabile

不安定な

불안정한

nestabilen

instabil

ไม่มั่นคง

dengesiz

không ổn định

不稳定的

unstable

[ˈʌnˈsteɪbl] ADJ

1. (= unsafe) [building, construction] → inestable, poco firme, poco sólido

2. (= unpredictable) [condition, economy, prices] → inestable
the country is politically unstable → el país es inestable desde el punto de vista político

3. [weather] → inestable, variable

4. (Psych) [person, character] → inestable
mentally/emotionally unstable → mentalmente/emocionalmente inestable

5. (Phys) [matter, molecule] → inestable

Collins Spanish Dictionary - Complete and Unabridged 8th Edition 2005 © William Collins Sons & Co. Ltd. 1971, 1988 © HarperCollins Publishers 1992, 1993, 1996, 1997, 2000, 2003, 2005

unstable

[ʌnˈsteɪb^əl] adj

(= likely to move or fall) [rock formation, ladder] → instable

(= volatile) [situation, government, share prices] → instable

(emotionally) [person] → instable

(CHEMISTRY, PHYSICS) [compound, particle, isotope] → instable

unstable

adj

structure → nicht or wenig stabil; foundations also, area → unsicher; vehicle, government, country → instabil; weather → unbeständig; economy → unsicher, schwankend; prices → schwankend; (Chem, Phys) → instabil; the patient is in an unstable condition → der Zustand des Patienten ist labil or nicht stabil

(Psych, mentally) → labil; mentally/emotionally unstable → geistig/emotional labil

Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007

unstable

[ʌnˈsteɪbl] adj (structure, situation) (Chem, Phys) → instabile; (person) → squilibrato/a

unstable

→ غَيْرُ مُسْتَقِرّ nestabilní ustabil instabil ανισόρροπος inestable horjuva instable nestabilan instabile 不安定な 불안정한 onstabiel ustabil chwiejny instável нестабильный instabil ไม่มั่นคง dengesiz không ổn định 不稳定的

unstable

a. inestable;

___ angina → angina ___;

___ bladder → vejiga ___.

unstable

adj inestable

References in classic literature ?

Similarly, you may sometimes find on a mountain-side a large rock poised so delicately that a touch will set it crashing down into the valley, while the rocks all round are so firm that only a considerable force can dislodge them What is analogous in these two cases is the existence of a great store of energy in unstable equilibrium ready to burst into violent motion by the addition of a very slight disturbance.

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Nor would I now attempt to trace The more than beauty of a face Whose lineaments, upon my mind, Are -- shadows on th' unstable wind: Thus I remember having dwelt Some page of early lore upon, With loitering eye, till I have felt The letters - with their meaning - melt To fantasies - with none.

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A heart weary and flippant; an unstable will; fluttering wings; a broken backbone.

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And yet on this unstable and death-terrific substance of which he was well aware Van Horn was composed, he trod heavily with his personality, daring, to the verge of detonation, to impact it with his insolence.

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Both men and ships live in an unstable element, are subject to subtle and powerful influences, and want to have their merits understood rather than their faults found out.

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The steerage was the lair of this pack, and, out of the steerage, it ranged the whole world, which was the Mary Turner ever rocking, heeling, reeling on the surface of the unstable sea.

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He had always been unstable of purpose and weak of will, never keeping to one course long.

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Though his wife had proved unstable his children were left to him.

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"Go not ungirt and loose, Sancho; for disordered attire is a sign of an unstable mind, unless indeed the slovenliness and slackness is to he set down to craft, as was the common opinion in the case of Julius Caesar.

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Complaints are everywhere heard from our most considerate and virtuous citizens, equally the friends of public and private faith, and of public and personal liberty, that our governments are too unstable, that the public good is disregarded in the conflicts of rival parties, and that measures are too often decided, not according to the rules of justice and the rights of the minor party, but by the superior force of an interested and overbearing majority.

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Then I had to look down at the unstable hooks to which I clung.

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Such stand simply elevated upon the goodwill and the fortune of him who has elevated them--two most inconstant and unstable things.