UNSTABLE

Pronunciation (US):

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IPA (US):

 Dictionary entry overview: What does unstable mean? 

• UNSTABLE (adjective)
  The adjective UNSTABLE has 6 senses:

1. lacking stability or fixity or firmness

2. highly or violently reactive

3. affording no ease or reassurance

4. suffering from severe mental illness

5. disposed to psychological variability

6. subject to change; variable

  Familiarity information: UNSTABLE used as an adjective is common.

 Dictionary entry details 

• UNSTABLE (adjective)

Sense 1

Meaning:

Lacking stability or fixity or firmness

Context example:

an unstable world economy

Similar:

explosive; volatile (liable to lead to sudden change or violence)

volcanic (explosively unstable)

tottering ((of structures or institutions) having lost stability; failing or on the point of collapse)

top-heavy (unstable by being overloaded at the top)

tipsy (unstable and prone to tip as if intoxicated)

seismal; seismic (subject to or caused by an earthquake or earth vibration)

rocky (liable to rock)

rickety; shaky; wobbly; wonky (inclined to shake as from weakness or defect)

crank; cranky; tender; tippy ((used of boats) inclined to heel over easily under sail)

coseismal; coseismic (being where earthquake waves arrive simultaneously)

Also:

impermanent; temporary (not permanent; not lasting)

inconstant (likely to change frequently often without apparent or cogent reason; variable)

unsteady (subject to change or variation)

Antonym:

stable (resistant to change of position or condition)

Derivation:

unstableness (the quality or attribute of being unstable and irresolute)

Sense 2

Meaning:

Highly or violently reactive

Context example:

sensitive and highly unstable compounds

Similar:

reactive (participating readily in reactions)

Derivation:

unstableness (the quality or attribute of being unstable and irresolute)

Sense 3

Meaning:

Affording no ease or reassurance

Synonyms:

precarious; unstable

Context example:

a precarious truce

Similar:

uneasy (lacking a sense of security or affording no ease or reassurance)

Derivation:

unstableness (the quality or attribute of being unstable and irresolute)

Sense 4

Meaning:

Suffering from severe mental illness

Synonyms:

mentally ill; unsound; unstable

Context example:

of unsound mind

Similar:

insane (afflicted with or characteristic of mental derangement)

Derivation:

unstableness (the quality or attribute of being unstable and irresolute)

Sense 5

Meaning:

Disposed to psychological variability

Context example:

his rather unstable religious convictions

Similar:

irresolute (uncertain how to act or proceed)

Derivation:

unstableness (the quality or attribute of being unstable and irresolute)

Sense 6

Meaning:

Subject to change; variable

Synonyms:

fluid; unstable

Context example:

everything was unstable following the coup

Similar:

changeable; changeful (such that alteration is possible; having a marked tendency to change)

 Context examples 

This alteration yields an unstable cytochrome P450 2C19*12 protein that is predicted to have an additional 26 amino acids.

(CYP2C19*12 Allele, NCI Thesaurus)

To be unstable, having ups and downs.

(Fluctuate, NCI Thesaurus)

This is the first unstable radioactive molecule definitively detected outside of the Solar System.

(Stellar Corpse Reveals Origin of Radioactive Molecules, ESO)

All his weight was on one foot, and he was in a state of unstable equilibrium.

(White Fang, by Jack London)

Epipropidone is not used clinically due to its unstable nature.

(Epipropidine, NCI Thesaurus)

A white, crystalline powder that is very unstable in the presence of light but fairly heat resistant.

(Ochratoxin A, NCI Thesaurus)

This unstable electron configuration causes these chemicals to be highly reactive with other molecules.

(Oxygen radical, NCI Thesaurus)

This is the first time that the rare and unstable mineral has been found in such a large quantity and the first time it has been found to be associated with plants.

(Rare mineral discovered in plants for first time, University of Cambridge)

A type of unstable molecule that contains oxygen and that easily reacts with other molecules in a cell.

(Oxygen radical, NCI Dictionary)

Free radicals are unstable molecules that are made during normal cell metabolism (chemical changes that take place in a cell).

(Catechin, NCI Dictionary)